What is the mass of 4.32 mol GaI3?
455 g
1,230 g
1,720 g
1,950 g

Answers

Answer 1

Answer:

D. 1,950 g

Explanation:

I completed the test and it is the correct answer!

Answer 2

The mass of one mole of gallium iodide GaI₃ is 449.7 g/mol. Hence, the mass of 4.32 moles of GaI₃ is 1950 g.

What is gallium iodide?

Gallium iodide is a covalent compound formed by the electron sharing between Ga and three iodine atoms. Ga has three valence electrons and each is shared with three iodine and each iodine in turn shares 3 electrons to Ga.

Atomic mass of Ga = 69 g/mol

Atomic mass of I = 126.9 g/mol

mass of 3 iodine atoms  = 3 ×  126.9 = 380.7 g

Molar mass of GaI₃ = 380.7 + 69 = 449.7 g.

Molar mass of a compound is the mass of one mole of the compound. Hence, one mole of the compound is 449.7 g. Mass of 4.32 moles is :

4.32 × 449.7 ≅1950 g.

Therefore, the mass of 4.32 moles of  GaI₃ is approximately 1950 g.

To find more on gallium iodide, refer here:

https://brainly.com/question/13745972

#SPJ2


Related Questions

The frequency of a wave does not change as it passes from one medium to another.
What will most likely happen if a light wave moves from the air into a solid?

A. The wavelength of the light wave will increase.
B. The speed of the light wave will decrease.
C. The wavelength of the light wave will remain the same.
D. The speed of the light wave will remain the same.

Answers

Answer:

When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn. The wave is slower but the wavelength is shorter meaning frequency remains the same.

What is the volume of 2.43 x 1023 molecules of N2 gas at STP

Answers

Answer:

9.05L

Explanation:

Use information from the reaction to design an experiment that could be used to remove the tarnish (Ag2S) from a silver fork

Answers

Line a basin with foil, add a teaspoon of bicarbonate of soda and a sprinkle of salt, and then pour in hot water. The tarnished silver object may then be immersed in water, ensuring sure it comes into touch with the aluminum foil, as well as the silver sulphide tarnish will quickly dissipate.

Tarnish is caused by a chemical interaction between silver and sulfur-containing compounds in the air. Silver sulphide is formed when silver combines with sulphur. Silver sulphide is a dark substance. A thin layer of silver sulphide grows on the surface of silver, darkening it.

Experimental design is a technique that enables scientists and engineers to efficiently assess the effect of multiple inputs, or factors, on measures of performance, or responses. A bone density research, for example, contains three experimental groups: a control group, the stretching exercise group, as well as a jumping exercise group. In a between-subjects experiment, investigators allocate each participant to one of three groups at random. While silver is the most commonly linked with tarnishing, it may occur on almost every metal, including aluminum, copper, and brass.

To know more about the Experiment Design, here

https://brainly.com/question/1418338

#SPJ4

lead can react with oxygen gas. If lead (IV) oxide is the product of the reaction, how would the reaction be classified

Answers

Answer:

this reaction is an oxidation reaction

The chemical reactions involving both oxidation and reduction are known as redox reactions. The oxidation involves the loss of electrons. The reaction of lead with oxygen is an example of oxidation reaction.

What is oxidation reaction?

According to the classical concept, oxidation is defined as a process which involves the addition of oxygen or electronegative element or the removal of hydrogen or electropositive element.

During electron transfer, the species which loses electrons is said to be oxidized and the species which gains electrons is said to be reduced.

The lead (IV) oxide is the formula of PbO₂. Here the oxidation state of lead is +4. The lead (IV) oxide is used in manufacturing dyes and also used to make explosives. It is a corrosive outcome that can evolve in lead pipes that are used for drinking water.

The formation of lead (IV) oxide is given as:

Pb (s) + O₂ (g) → PbO₂ (g)

Thus the reaction is an oxidation reaction.

To know more about oxidation reaction, visit;

https://brainly.com/question/29218241

#SPJ2

The heat of vaporization for water is 40.7 kJ/mol. How much heat energy must 150.0 g of water absorb to boil away completely

Answers

The heat of vaporization for water is 40.7 kJ/mol. the heat energy must 150.0 g of water absorb to boil away completely is 6106 kJ.

The expression is given as :

q = m ΔH

where ,

q is heat energy

m is the mass

ΔH is the heat of the vaporization.

q = heat = ?

m = mass  = 150 g

ΔH = heat of vaporization = 40.7 kJ/mol

q = 150 × 40.7

q = 6106 kJ

Thus , if the heat of vaporization is 40.7 kJ/mol ,the heat energy required for 150 g of water absorb to boil away completely is 6106 kJ.

To learn more about heat vaporization here

https://brainly.com/question/24569455

#SPJ4

Which of the following could account for the weakening of hurricanes when they reach the Atlantic Ocean? Ocean waters in the Atlantic . .

A.) decrease in temperature.
B.) increase in temperature.
C.) decrease in salinity.
D.) increase in salinity.

Answers

A decrease in temperature could account for the weakening of hurricanes when they reach the Atlantic Ocean. hence option A is the correct answer.

How is Hurricane formed?

There must be warm ocean water and wet, humid air in the area for one to form. When humid air flows upward at a low-pressure zone over warm ocean water, water is released from the air, resulting in storm clouds. The air in a hurricane rotates as it rises.

Hurricanes begin with the evaporation of warm seawater, which causes water to be pumped into the lower atmosphere. When converging winds collide and turn upwards, this humid air is pulled aloft.

Hurricanes arise when warm, moist air rises over sea. Cooler air replaces the rising air. Large clouds and thunderstorms continue to form as a result of this process. Because of the Coriolis Effect, these thunderstorms continue to expand and begin to rotate.

Learn more about Hurricane here:

https://brainly.com/question/18221136

#SPJ1

A scientist distilled a quantity of water to use in an experiment. How much water did he collect if the condensation process released 9040 J of energy? H2O (l) -> H2O (g) ΔHv=2260 J/g a 0.0138 mol b 0.222 mol c 4.00 mol d 0.250 mol I really need the answer plz

Answers

Answer:

I know this is very late I am sorry, but

I believe your answer would be C) 4.00 mol.

Correct me if I am wrong.

Explanation:

9040 divided by 2260= 4

0.222 moles of water  released 9040 J of energy.

The heat of vaporization is defined as the heat required to convert 1 g of a substance from liquid to vapor. We are told that the heat of vaporization of water is 2260 J/g.

Hence;

1g of water releases  2260 J of heat

xg of water releases  9040 J of heat

x = 1g ×  9040 J /2260 J

x = 4 g

1 mole of water contains 18 g

x moles of water contains 4 g

x = 1 mole  × 4 g/18 g

x = 0.222 moles

Learn more: https://brainly.com/question/10165688

-intervención de los neurotransmisores de la felicidad y de la tristeza en los trastornos de la bipolaridad. Como estimular los neurotransmisores de la felicidad en nuestro cuerpo.


doy 5 estrellas

Answers

Answer:   Desarrollar y ceñirse a un horario diario puede ayudar a estabilizar los cambios de humor del trastorno bipolar. Incluya horarios establecidos para dormir, comer, socializar, hacer ejercicio, trabajar y relajarse. Trate de mantener un patrón regular de actividad incluso durante los altibajos emocionales.

Explanation:

PLEASE HELP
What is the difference between a soap an detergent?

1. Soaps have long hydrocarbon chains and detergents have long nitrogen chains,

2. Detergents contain carboxylic acid groups and soaps contain phosphoric acid groups.

3. Detergents have long hydrocarbon chains and soaps have long nitrogen chains.

4. Soaps contain salts and detergents contain sulfonic or phosphoric acid groups.

Answers

I think the answer should be 4 because detergents contain phosphoric acid

A mixture contains only NaCl and Al2(SO4)3. A 1.68-g sample of the mixture is dissolved in water and an excess of NaOH is added, producing a precipitate of Al(OH)3. The precipitate is filtered, dried, and weighed. The mass of the precipitate is 0.116 g. What is the mass percent of Al2(SO4)3 in the sample

Answers

The precipitate is collected, filtered, dried, and weighed.. The mass of the precipitate is 0.116 g.

What is dissolved?

Dissolved refers to a solute that is completely dissolved in a solvent, resulting in a homogeneous mixture. When a solute, such as a salt, is dissolved in a solvent, such as water, the molecules of each component are dispersed evenly throughout the mixture. This process can be reversed by evaporating the solvent, leaving the solute behind. The amount of solute that can be dissolved in a particular solvent is known as its solubility.

Mass of Al2(SO4)3= Mass of sample- Mass of precipitate
Mass of Al2(SO4)3= 1.68-0.116=1.564 g
Percent of Al2(SO4)3= (1.564/1.68)*100= 93.45 %

To learn more about Dissolved
https://brainly.com/question/2078413
#SPJ4

what point is swift makihng in a modest proposel by discounting other people and more humane solutions

Answers

Making people aware of how terrible hunger and poverty are in contemporary society is the aim of A Modest Proposal.

These kinds of problems are still important in today's culture and are not only confined to Swift's day. Jonathan Swift wrote an article titled "A Modest Proposal" that discusses hunger and poverty. Swift created it in 1729 as a means of drawing attention to how terrible these issues were.Most likely, this idea did seem excessive to many of his contemporaries, especially if they failed to grasp the text's satirical and sarcastic tone. Swift is trying to make a point about how things between the rich English and the poor Irish have gotten out of hand.

To learn more about Swift's please click on below link

https://brainly.com/question/15272045

#SPJ4

Given that 1 kWh = 3. 6 MJ and that 1 Btu = 1055 J, show that 1 kWh = 3412 Btu.

Answers

Given that 1 kWh = 3. 6 MJ and that 1 Btu = 1055 J, It is shown that 1 kWh = 3412 Btu.

1 kilowatt (kWh) = 3.6 mega Joules (MJ)

1 British thermal unit (Btu) = 1055 Joules (J)

As we know that:

1 MJ = 1000000 J

Since

1 kWh = 3.6 x 1000000 J

Calculate for 1 J

1 J = 1 ÷ 1055 Btu

1 kWh = 3.6 x 1000000 x (1 ÷ 1055) Btu

1 kWh  = 3412.32 Btu

So it is calculated that 1 kilowatt (kWh) is equal to 3412 British thermal units (Btu).

You can also learn about British thermal unit (Btu) from the following question:

https://brainly.com/question/19431525

#SPJ4

2
Select the correct answer from each drop-down menu.
How are real gases different from ideal gases?
Real gases differ from ideal gases because in a real gas,....

Answers

Answer:

Real gases particles are smaller than ideal gases

m
4. You are carrying your 9-kg backpack to school. If your mass is 64 kg and you are walking with an acceleration of 2.5
what is your force?
O 160 N
29.2 N
2 183 N
O 22.5 N

Answers

Answer:

183N

Explanation:

183N we have to add both mass

Answer:

184N is my force wen carting a backpack

Prior to Thomson's discovery, the atom was thought to be indivisible. Explain the significance of Thomson's concept of the electron.

Answers

In 1897, J.J. Thomson's discovery of the electron was revolutionary.

What is thomson's concept?

Thomson's concept of the electron showed that the atom was not indivisible, but instead was composed of smaller particles. This discovery provided the first piece of evidence to support the atomic theory, which states that all matter is made up of atoms.

Thomson's concept of the electron also allowed scientists to understand the behaviour of electricity better. Electrons are negatively charged particles, and Thomson's discovery showed that electricity is a flow of electrons. This knowledge allowed scientists to create new technologies based on the understanding of electrons, such as computers and cell phones.

The significance of Thomson's concept of the electron can be summed up in three words: evidence, electricity, and technology. Thomson's discovery provided the first piece of evidence for the atomic theory, allowed for a better understanding of electricity, and paved the way for the creation of many new technologies.

To know more about thomson's concept click-https://brainly.com/question/1569426
#SPJ4

Why are the elements in Groups 1 and 17 so reactive?

Answers

Fluorine as well as chlorine are among the substances in group 17. Alkali metals as well as hydrogen are both part of group 1 on the periodic table.

Group 1 elements were extremely reactive due to the fact that they only contain one valence electron. As just a result, atoms were only ever combined with some other elements present in nature.

Due to their size as well as low ionisation enthalpy, alkali metals were extremely reactive metals. Moving lower in the group causes them to become more reactive. Reactivity to air: These metals discolor when exposed to dry air because oxides create, which then react with moisture to generate hydroxides.

To know more about Reactivity

https://brainly.com/question/1598581

#SPJ4

For your new candle-making business, you need to purchase a large amount of a unique scented wax. You plan to charge $9. 95 per large candle. The wax you need is availbale form a U. S. Supplier for $25. 53/1b and also from a German supplier for €11. 90/kg. The current exchange rate is $1=€0. 76 and 1 kg=2. 20 lb

What is the price of the wax from the U. S. Supplier in €/kg?

What is the price of the wax from the German supplier in $/lb

Answers

The price of the wax from the U.S. supplier in €/kg would be: €25.53 / 2.20 lb = €11.67/kg.

The price of the wax from the German supplier in $/lb would be $11.90 / 0.76 = $15.68/lb.

This price is calculated by taking the cost of the wax in US dollars and converting it to Euros using the current exchange rate of $1 = €0.76.

This price is calculated by taking the cost of the wax in Euros and converting it to US dollars using the current exchange rate of $1 = €0.76. It's important to note that the price of the wax from the German supplier is higher than the price from the US supplier when converted to dollars per pound.

This is because the price per kg is lower but the conversion to pound makes it higher.

The price of the wax from the U.S. supplier in €/kg would be: €25.53 / 2.20 lb = €11.67/kg.

The price of the wax from the German supplier in $/lb would be $11.90 / 0.76 = $15.68/lb.

To learn more about Pricing,

https://brainly.com/question/25716956

#SPJ4

when 8 moles of nh3 was used in a reaction how many mole of o2 needs to be used

Answers

Answer: Uhmmmm what dude i dont know what to say how the heck so i solve this?

Explanation:

If 6.00 L of 3.00 M HCl is added to 5.00 L of 2.00 M Ca(OH)2, which species will be the limiting reactant

Answers

HCl will be the limiting reactant for the above question

When HCl and Ca(OH)2 are mixed, they react to form water and calcium chloride (CaCl2) according to the following equation: HCl(aq) + Ca(OH)2(aq) -> CaCl2(aq) + 2H2O(l). To determine which species is the limiting reactant, we need to compare the amount of HCl and Ca(OH)2 present in the reaction.The number of moles of HCl present in the reaction is given by the equation n=CV, where n is the number of moles, C is the concentration of the solution and V is the volume. Hence  number of HCL moles is:

n = 3.00 M 6.00L = 18.0 moles The number of moles of Ca(OH)2 present in the reaction is given by the equation n=CV, where n is the number of moles, C is the concentration of the solution and V is the volume. So the number of moles of Ca(OH)2 is: n = 2.00 M 5.00L = 10.0 moles. The number of moles of HCl is greater than the number of moles of Ca(OH)2, so HCl will be the limiting reactant.

Learn more about limiting reactant here:

https://brainly.com/question/14225536

#SPJ4

Calculate ΔS∘ for Ti(s)+2Cl2(g)→TiCl4(g)
Express your answer using four significant figures.

Answers

ΔS∘ for Ti(s)+2Cl2(g)→TiCl4(g) is 659.6J/mol.. It is important to note that, as a general rule, a positive ΔS° indicates an increase in disorder and a negative ΔS° indicates a decrease in disorder.

The change in entropy (ΔS) for a chemical reaction can be calculated using the standard entropies (S°) of the reactants and products.

ΔS° = S°(products) - S°(reactants). For the reaction Ti(s) + 2Cl2(g) → TiCl4(g)S° of Ti(s) = 29.1 J/mol·K, S° of Cl2(g) = 223.1 J/mol·K, S° of TiCl4(g) = 167.4 J/mol·K. Therefore, ΔS° = (S°(TiCl4) + 2S°(Cl2)) - S°(Ti)ΔS° = (167.4 + 2*223.1) - 29.1 = 659.6 J/mol·K. So the ΔS∘ for Ti(s) + 2Cl2(g) → TiCl4(g) is 659.6 J/mol·K with four significant figures. It is important to note that, as a general rule, a positive ΔS° indicates an increase in disorder and a negative ΔS° indicates a decrease in disorder. So in this case, the process of going from solid titanium and gaseous chlorine to gaseous titanium tetrachloride increases disorder, which is consistent with a positive ΔS°.

To learn more about ΔS here:

https://brainly.com/question/3784176

#SPJ4

the diameter of a sodium atom, na, is larger than the diameter of a sodium ion, na , because the sodium ion has

Answers

Na+ has one fewer electron than Na, making it smaller and possessing a higher effective nuclear charge.

The fact that sodium ions have just two electron shells makes them smaller than sodium atoms for the main reason (the atom has three). Because they both have the same number of nucleons, the Na+ ion and Na atom have the same nuclear charge. Na+, on the other hand, has a smaller nuclear charge than Na because it has one fewer electron. Na+ is therefore smaller than Na because there is more attraction on the electrons that are already there. A sodium ion's size is smaller than that of a sodium atom.

Learn more about Nuclear Charge

brainly.com/question/17102072

#SPJ4

SEP Compare Data Look at the data in Figure 2. Which is the most
electronegative
atom? Which is the least?

Answers

The most electronegative atom is Flourine and the least is Hydrogen

How is fluorine the one with most electronegative atom?

The attached image indicates how the highly electronegative Fluorine atom takes away most of the electron density (red-to-blue colored cloud) from a hydrogen–fluoride covalent bond.

An electronegative atom is an atom that has a tendency to attract electrons towards itself when it is part of a chemical bond. The most common example is the oxygen atom. The ability of an atom to attract electrons is known as its electronegativity.

The higher the electronegativity of an atom, the more it will pull electrons towards itself. The electronegativity of an atom is determined by its atomic number and the number of electrons in its outermost shell.

Therefore, the correct answer is as given above

learn more about electronegative atom: https://brainly.com/question/24977425

#SPJ1

5 difference between Ionic compound and covalent compounds in tabular form

Answers

1. Ionic compounds are formed by the transfer of electrons that are positively and negatively charged, whereas, covalent compounds are formed by sharing the electrons. 2. In an ionic compound, bonding involves a metal and nonmetal, whereas, in the covalent compound, bonding is between nonmetals.

Diatomic elements are important. what makes them different from other elemental substances?

Answers

Diatomic elements are elements that exist as pairs of atoms. Unlike other elemental substances, diatomic elements cannot exist as single atoms, but must exist as a pair of atoms bound together.

What is elemental?

Elemental refers to an element or substance made up of one kind of atom, such as oxygen, carbon, or hydrogen. Elements are the basic building blocks of matter, and they are combined in different ways to form the molecules of different materials. Elemental substances are the most basic form of matter, and they are essential for life on Earth. There are currently 118 known elements, and they are found in nature and in many products. Each element has unique properties, and they can be used in different ways. For example, oxygen is essential for human respiration, while carbon is found in many materials, such as plastics and diamonds.

Examples of diatomic elements include nitrogen (N2), oxygen (O2), hydrogen (H2), chlorine (Cl2), fluorine (F2), and bromine (Br2).

To learn more about elemental
https://brainly.com/question/18096867
#SPJ4

help help help help help helps​

Answers

Answer:

C may be the correct answer

In the last minute rush to assemble the demonstration, your teacher spills the lead chloride all over their sandwich and is left with 57.2 grams in the bottle. How much potassium iodide should be weighed out to convert all of the lead chloride to product?

Answers

Answer: Magnesium is being oxidized, and the chloride ion is being reduced. ... solutions of the reactants lead(II) nitrate and potassium iodide.

Explanation:

An enzyme's specificity can be due to: Group of answer choices amount of substrate available molecular recognition based on structural complementarity the ratio of catalyzed rate to the uncatalyzed rate of reaction. amount of enzyme produced by the cell.

Answers

Answer:

molecular recognition based on structural complementarity

Explanation:

Enzymes work on the basis of a lock and key model. The substrates on which enzymes act are specifically tailored to suit the shape of the enzyme.

As such, the enzyme just fits into the substrate in the same way as the right key fits into a lock.

Hence, molecular recognition based on structural complementarity is the basis for the specificity of enzyme activity.

Which component of the periodic table is needed to determine why KCl tastes like NaCl? A. Group B. Period C. Atomic Weight D. Atomic Number

Answers

Atomic Number of the periodic table is needed to determine why KCl tastes like NaCl.

What is the Periodic Table?

The Periodic Table is a tabular arrangement of the chemical elements organized by atomic number, electron configuration, and recurring chemical properties. It is one of the most important tools in chemistry, providing a useful framework to classify, systematize, and predict the properties of elements.

Atomic numbers are used to identify each element in the periodic table, and they are also used to determine the number of protons in the nucleus of an atom. The number of protons in an atom determines its chemical properties, and the similarity in the number of protons between two elements can explain why they have similar properties. In this case, the similarity in the atomic number of potassium (K, atomic number 19) and sodium (Na, atomic number 11) explains why the salts of both elements, potassium chloride (KCl) and sodium chloride (NaCl), taste the same.

Hence, Option D is correct.

To know more about the Periodic Table,

https://brainly.com/question/15987580

#SPJ4

What is the type of mutation represented by the amino acid sequence below?

Correct sequence: Leucine – Alanine – Glycine – Leucine
Mutated sequence: Leucine – Alanine – Valine – Leucine

Answers

Answer:

Substitution mutation

Explanation:

A substitution mutation is a type of mutation in which one or more nucleotide base is replaced by another in a sequence. This will result in the replacement of one or more amino acid in the amino acid sequence.

This is the case in this question where the original amino acid sequence was given as: Leucine – Alanine – Glycine – Leucine. After mutation, the following mutated sequence was produced: Leucine – Alanine – Valine – Leucine.

As illustrated above, one would notice that there is replacement of GLYCINE amino acid by VALINE in the mutated sequence, hence, it is an example of SUBSTITUTION MUTATION.

ASAP HELP
This question is about acids and bases.
What is the pH of sulfuric acid?
Tick () one box.
1
7
14

Answers

Answer:

the answer is 2.75 but since that isn't an option I'd go with 1 because I just took a test with this question and it was the right answer.. hopefully that helps

Other Questions
Suppose that 15 inches of wire costs 90 cents. At the same rate, how many inches of wire can be bought for 72 cents? if a researcher wanted to temporarily denature a protein but wanted to be sure it would refold, which of the following methods or substances would be most appropriate Which of the following best describes a central idea of the text? When good people do bad things common lit HELP I NEED HELP ASAP HELP I NEED HELP ASAP HELP I NEED HELP ASAP HELP I NEED HELP ASAPHELP I NEED HELP ASAP HELP I NEED HELP ASAP HELP I NEED HELP ASAP HELP I NEED HELP ASAP The steps to solve an equation are shown below. Choose the reasons that are listed in the correct order to justify the steps in the solving process.A- 1. Given, 2. Division Property of Equality, 3. Addition Property of Equality, 4. Division Property of EqualityB- 1. Given, 2. Multiplication Property of Equality, 3. Subtraction Property of Equality, 4. Division Property of EqualityC- 1. Given, 2. Division Property of Equality, 3. Addition Property of Equality, 4. Multiplication Property of EqualityD- 1. Given, 2. Multiplication Property of Equality, 3. Addition Property of Equality, 4. Division Property of Equality How does opportunity cost affect the decisions of individuals or government? The Red Cross was started in Carefully retype this sentence using correct capitalization.after several winter storms, jeff couldn't wait for the weather to improve. What words do I capitalize, and which ones do I leave alone? what do you think will happen to your unfinished report? please answer:( A circle of radius 8 cm is cut into 6 partsof equal size, as shown in the diagram.Calculate the area of each part, givingyour answer correct to 2 decimal places. N a circuit, when the two conductors leading from the power source touch metal-to-metal, this is called a _____ circuit HELP ASAP pleaseee. I'm not sure how to answer this question in the picture. What is the area of a circle with a radius of 5? When this operator is used with string operands it concatenates them, or joins them together.Select one:a. &b. *c. %d. +e. None of these A walkway forms one diagonal of a square playground. The walkway is 32 m long. How long is each side? Only answer if youre sure :) need the whole answer! Will give Brainly You are handed a pring that i 0. 400 m long. You hang the pring from a hookon the ceiling and attach a 0. 750-kg ma to the other end of the pring. Thetretched pring length i 0. 450 m. What i the pring contant? Can someone help me out. Paying big points Write sentences that describe what the people in the drawings were doing yesterday at three o'clock in the afternoon. Use the subjects providedand the imperfect tense.Example- You see: (a picture of a girl swimming] MariaYou write: Mara nadaba en el mar.(The person in the picture is writing) When a chemical reaction occurs in a sealed container, what is the total mass after the reaction compared to the total mass before the reaction? A. the same B. less C. more D. variable