Answer:
a chemical change
Explanation:
a physical change is mostly identified even without indicators i.e candle wax about forming a new acid or base I guess we have to include a ph scale to ascertain since the salt can be acidic but not necessarily an acid
Answer: The answer is A, a chemical change has occurred
Explanation:
I’m just a jenious
Consider a pure crystalline solid that is heated from absolute zero to a temperature above the boiling point of the liquid. Which of the following processes produces the greatest increase in the entropy of the substance?
a) melting the solid
b) heating the liquid
c) heating the gas
d) heating the solid
The question is incomplete, the complete question is;
Consider a pure crystalline solid that is heated from absolute zero to a temperature above the boiling point of the liquid. Which of the following processes produces the greatest increase in the entropy of the substance? A ) melting the solid B ) heating the gas C ) vaporizing the liquid D ) heating the solid E ) heating the liquid
Answer:
vaporizing the liquid
Explanation:
We generally define entropy in chemistry as the degree of disorderliness in a system. The entropy of gases is greater than that of liquids and the entropy of liquids is greater than that of solids. It then logically follows that the degree of entropy in gases is the greatest among all the states of matter while the entropy of solids is the least among all the states of matter since solid particles remain in their mean positions and can only vibrate or sometimes rotate. Liquid particles may translate while gaseous particles move at high velocity with negligible intermolecular forces of attraction between them.
A phase transition from liquid to gaseous state now represents the greatest change in the entropy of the system since gases posses the highest entropy among all the states of matter, hence the answer.
How many moles of ZnCl2 will be produced from 61.0 g of Zn, assuming HCl is excess?
Answer: 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
moles of zinc:
[tex]\text{Number of moles}=\frac{61.0g}{65g/mol}=0.938moles[/tex]
[tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]
As HCl is in excess , zinc is the limiting reagent and it limits the formation of product.
According to stoichiometry :
1 mole of Zn produce = 1 mole of [tex]ZnCl_2[/tex]
Thus moles of Zn produce = [tex]\frac{1}{1}\times 0.938=0.938[/tex] moles of [tex]ZnCl_2[/tex]
Thus 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Based on the kinetic molecular theory, which of the following statements is correct about the particles in a sample of gas at a constant temperature and
volume?
They have negligible kinetic energy
They attract each other with strong forces.
There is a lot of empty space between them.
Their net kinetic energy decreases due to collisions.
Answer:
There is a lot of empty space between them.
Explanation:
The kinetic molecular theory postulates that a substance is made up of tiny particles called molecules. The molecules of a gas are in constant random motion and collide elastically with each other. They also collide with the walls of the container.
The magnitude of intermolecular forces of attraction between gas molecules is very small. Hence gas molecules are largely apart with a lot of empty space between gas molecules.
Answer:C, There is a lot of empty space between them.
Explanation:
Name the layer where the pressure is 3.5 million atmospheres:
Answer:
The Inner Core
hope it was useful
stay at home stay safe
keep rocking
pls mark me as brani
........
Which statement is true with respect to the investigation? The student investigated only the physical properties of lead. The student investigated only the chemical properties of lead. The student investigated more physical properties than chemical properties of lead. The student investigated more chemical properties than physical properties of lead.
The question is incomplete, the complete question is;
A student investigated some properties of lead and recorded the findings in the table below. Property Observation Color Dull gray Density 11.3 g/cm3 Volume of sample 3 cm3 Melting point 327°C Reaction with air Lead oxide forms on the surface Electrical conductivity Conducts some electricity Which statement is true with respect to the investigation?
A. The student investigated only the physical properties of lead.
B. The student investigated only the chemical properties of lead.
C. The student investigated more physical properties than chemical properties of lead.
D. The student investigated more chemical properties than physical properties of lead.
Answer:
The student investigated more physical properties than chemical properties of lead.
Explanation:
If we look at the things mentioned in the question as regards the approach of the student towards the study of lead, we will discover that he/studied;
Colour, density, volume, melting point and electrical conductivity which are all physical properties. Physical properties of a substance does not involve chemical reactions of the substance under study.
The only chemical property studied by the student is its formation of an oxide- lead oxide with air as follows;
2Pb(s) + O₂(g) → 2PbO(s)
Thus we can safely conclude that; the student investigated more physical properties than chemical properties of lead.
Answer:
c
Explanation:
edge 2021 :)
A sample of a certain barium chloride hydrate, BaCl2.nH2O, has a mass of 7.62 g. When this sample is heated in a crucible, it is converted to anhydrous barium chloride and water, with the water escaping as steam during the process. The mass of the solid anhydrous residue that remains in the crucible is 6.48 g. Determine the formula of this hydrate
Answer:
BaCl2.2H2O
Explanation:
Data obtained from the question include:
Mass of barium chloride hydrate (BaCl2.nH2O) = 7.62g
Mass of anhydrous barium chloride (BaCl2) = 6.48g
Next, we shall determine the mass of water in the barium chloride hydrate (BaCl2.nH2O). This can be obtained as follow:
Mass of water (H2O) = Mass of barium chloride hydrate (BaCl2.nH2O) – Mass of anhydrous barium chloride (BaCl2)
Mass of water (H2O) = 7.62 – 6.48
Mass of water (H2O) = 1.14g
Next, we shall write the balanced equation for the reaction. This is given below:
BaCl2.nH2O —> BaCl2 + nH2O
Next, we shall determine the masses of BaCl2.nH2O that decomposed and the mass H2O produced from the balanced equation.
Molar mass of BaCl2.nH2O = 137 + (35.5x2) + n[(2x1) + 16]
= 137 + 71 + n[2 + 16]
= (208 + 18n) g/mol
Mass of BaCl2.nH2O from the balanced equation = 1 x (208 + 18n) = (208 + 18n) g
Molar mass of H2O = (2x1) + 16 = 18 g/mol
Mass of H2O from the balanced equation = n x 18 = 18n g
Summary:
From the balanced equation above,
(208 + 18n) g of BaCl2.nH2O decomposed to produce 18n g of H2O.
Finally, we shall determine the formula for the hydrated compound as follow:
From the balanced equation above,
(208 + 18n) g of BaCl2.nH2O decomposed to produce 18n g of H2O.
But 7.62g of BaCl2.nH2O decomposed to produce 1.14g of H2O i.e
18n/(208 + 18n) = 1.14/7.62
Cross multiply
18n x 7.62 = 1.14(208 + 18n)
137.16n = 237.12 + 20.52n
Collect like terms
137.16n – 20.52n = 237.12
116.64n = 237.12
Divide both side by the coefficient of n i.e 116.64
n = 237.12/116.64
n = 2
Therefore the formula for the hydrate, BaCl2.nH2O is BaCl2.xH2O.
(c) He, Na, Mg (increasing order of melting point).
Answer:
Helium has melting point of - 272.2°C or - 458°F
Sodium (Na) = 650°C. or 208°C
Magnesium (Mg) = 97.79°C. Or 1202°F
Explanation:
In calculating the equilibrium constant for a reaction, the coefficients of the chemical equation are used as exponents for the factors in the equilibrium expression. TRUE FALSE
Answer: The given statement is TRUE.
Explanation:
An equilibrium reaction is one in which rate of forward reaction is equal to the rate of backward reaction.
Equilibrium constant is defined as the ratio of the product of the concentration of products to the product of the concentration of reactants each raised to their stochiometric coefficient.
For example for the given equilibrium reaction;
[tex]2H_2O(g)\leftrightharpoons 2H_2(g)+O_2(g)[/tex]
[tex]K_{eq}=\frac{[H_2]^2[O_2]}{[H_2O]^2}[/tex]
Thus the given statement that in calculating the equilibrium constant for a reaction, the coefficients of the chemical equation are used as exponents for the factors in the equilibrium expression is True.
sodium react gently with water ture or false
false,
sodium has a vigorous reaction with water.
This can be observed by putting a piece of sodium in water,
it moves swiftly across the surface of water and reacts violently.
An antacid tablet has a pH of about 9.5 which
means it is considered to be in the _____
range.
Acidic or basic
Answer:
Basic
Explanation:
The pH scale is a scale that tells us about the concentration of hydrogen ions in a solution.
Acids have many hydrogen ions. Acids have a pH of less than 7.
Bases have fewer hydrogen ions and more hydroxide ions. Bases have a pH of less than 14.
If the solution has a pH of exactly 7, then it is pure water. Water has the same concentration of hydrogen and hydroxide ions.
The antacid tablet has a pH of roughly 9.5 Since this is less than 14, but not equal to or less than 7, this must be an base. Therefore, it is considered to be in the basic range.
Answer:
9.5 is a base
Explanation:
A ph of less than 7 is an acid
7 is neutral
7 to 14 is a base
9.5 is a base
Which formula contains a metal and a nonmetal? SO2 MgO CO H2O
Answer:
MgO
Explanation:
Mg, which is magnesium, is considered a metal, when paired with Oxygen, which is a gas, it creates magnesium oxide, and the formula itself is a pairing of a metal with a nonmetal
Answer:
[tex]\boxed{MgO}[/tex]
Explanation:
Metals are red, nonmetals are blue, and metalloids are yellow in the attached file.
Using this table, you can see that Mg is a metal and O is a nonmetal, which fits the question criteria.
Hope this helps!
Explain this
When a small piece of glowing sodium is placed inside a gas jar filled with chlorine gas, the sodium continues to burn brightly but when the gas is replaced by argon gas, the glowing sodium becomes extinguished.
Answer:
Because Argon is a inert gas
Explanation:
Inert gases don't take place in any experiments
Answer:
Below.
Explanation:
The sodium reacts strongly with the chlorine to form NaCl and the heat of reaction continues the brightness, whereas it does not react with the inert gas argon and soon cools down.
Consider the hydrocarbon below. 2 carbons are double-bonded to each other; the pair are single bonded to H above left, above right, below right, and below left. What is the name of this hydrocarbon?
Answer:
Ethene.
Explanation:
To know the name of the compound given above, we must:
1. Determine the number of carbon present in the compound.
2. Determine whether a single, double or triple is present in the compound.
3. Combine the above to get the name.
Now, let us name compound given above. This is illustrated below:
1. The compound contains two (2) carbon atom.
2. The compound contains a double bond. Therefore, the compound is an alkene.
3. An alkene with two carbon atoms is called ethene.
Therefore, the name of the compound given in the question is called ethene.
Answer:
other guy is right :)
Explanation:
if you look up "ethene hydrocarbon" online, the image attached in the question pops up!
What are the ways in which quality of petrol can be improved?
Answer:
It can be improved by:
a) Adding METHANOL
b) Adding BUTANOL
c) Adding ETHANOL.
Explanation:
hope it helps.
Potassium hydrogen tartrate is an acid used in making cookies such as snicker doodles. (In your home, it is called cream of tartar.) It can be titrated with a base such as KOH to determine purity. A sample of 0.500 g is titrated to a pink endpoint with 21.58 mL of 0.1125 M KOH. Determine the percentage of potassium hydrogen tartrate (KHC4H4O6) in the sample. The acid/base ratio is 1:1.
Answer:
91.4%
Explanation:
Potassium hydrogen tartrate, KHT, reacts with KOH as follows.
KHT + KOH → H₂O + K₂T
where 1 mole of acid (KHT) reacts per mole o base (KOH), -That is acid/base ratio 1:1
The endpoint of a titration is the point in which moles of KOH = moles of KHT, you can see this endpoint with an indicator or doing a potentiometric titration.
As the endpoint requires 21.58mL = 0.02158L of a 0.1125M KOH, moles of KOH = moles of KHT are:
0.02158L × (0.1125mol / L) = 2.428x10⁻³ moles of KOH = moles of KHT
To convert these moles to grams you use molar mass of KHT (188.177g/mol):
2.428x10⁻³ moles of KHT × (188.177g / mol) = 0.457g of KHT are in the sample.
As you add 0.500g of sample, percentage of KHT in the sample is:
(0.457g / 0.500g) × 100 =
91.4%-That is the purity of the sample-
what kind of a compounds act as an electrolyte? explain with and example
Answer:
ionic compounds
Explanation:
just finished ap chem
Answer:
An ionic compound can act as an electrolyte. This is because an electrolyte should allow charges to travel inside it.
e.g = H2SO4, NaCl
Explanation:
A chemist is identifying an unknown solid substance that appears purple in color. Upon close inspection with a hand lens, she notices tiny grains in the substance. Some of the grains are blue; other grains are red. Based on this information, the substance is most likely a \
The question is incomplete, the complete question is;
A chemist is identifying an unknown solid substance that appears purple in color. Upon close inspection with a hand lens, she notices tiny grains in the substance. Some of the grains are blue; other grains are red. Based on this information, the substance is most likely a
a. Compound
b. Homogeneous Mixture
c. Pure substance
d. solution
e. heterogeneous mixture
Answer:
heterogeneous mixture
Explanation:
A heterogeneous mixture simply means a mixture of two different substances. If two substances are the same, they are expected to have the same colour or appearance.
We were told in the question that the colour of the mixture appeared purple. On close examination, the sample was found to comprise of two different substances of different colours; blue and red.
If there are two substances of different colours present in the sample, it then follows that the sample is a heterogeneous mixture.
The image shows information about the element carbon as it appears in the periodic table. Based on the image, which statement is accurate? A. A carbon atom has two protons, two neutrons, and two electrons. B. A carbon atom has three protons, six neutrons, and three electrons. C. A carbon atom has six protons, six neutrons, and six electrons. D. A carbon atom has four protons, four neutrons, and four electrons.
Answer:
C. A carbon atom has six protons, six neutrons, and six electrons.
Explanation:
Carbon has a relative atomic mass of 12 and an atomic number of 6. We must recall that the atomic number of an atom is the number of protons in that atom. The atomic number is also the same as the number of electrons in the neutral atom of that element.
To ensure electrical neutrality of the atom, the number of protons in the atom must be equal to the number of electrons in the atom.
The mass number of an atom is the sum of the number of protons and neutrons present in the atom. Since carbon has a mass number of 12, then there must be six neutrons present in the atom.
According to the electronic configuration and structure of atom statement which is true is that a carbon atom has six protons, six neutrons, and six electrons.The correct option is C.
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
The carbon atom has atomic number '6' giving it six electrons and six protons and neutrons each.Thus, option 'C' is correct.
Learn more about atom,here:
https://brainly.com/question/1566330
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Which of these elements have the smallest 1st ionization energy
Answer:
Ionization energy increases as you go across a period, and increases as you move up a group. So, elements with the smallest ionization energy would be at the bottom left corner of the periodic table. Examples of elements with small ionization energy: Francium (Fr), Cesium (Cs), Radium (Ra).
What's the meaning of love?
Answer: Love is when you feel like you can touch the sky when your around that person, when your at your best self or that person and when you put their needs before yours because your needs just don't matter. When you feel like you can't stop thinking about that person or you can stop smiling when you think of them. Its when you feel this warm, safe feeling when your around them. And if you really love them then my answer should be true for you.
Explanation:
because iv'e felt and have been in love before....
Answer:
Love is an intense, deep affection for another person. Love also means to feel this intense affection for someone. Love can also refer to a strong like for something or to like something a lot. Love has many other senses both as a verb and a noun
describe the smell of Na+ and H+
Answer:
Sodium ion ( Na+) is known to have no smell at all but however appears salty which is the reason why the compound Sodium Chloride has the same type of taste.
Hydrogen ions ( H+) are known to have no taste which implies it being tasteless. It is also important to note that it has no smell too when perceived (odorless).
Which of the following choices would have a negative entropy change? A. CaCO3(s)−>CaO(s)+CO2(g)
Answer: N2(g) + 3H2(g)- >2NH3(g) denotes a negative entropy change.
Explanation:
Entropy is defined as the extent of disorder in a system. The degree of entropy is more in a gas and less in a solid.
Here, 1st reaction produces ammonia from nitrogen and hydrogen. We can see that four moles of gases produces 2 moles of gaseous product. So the degree of disorder in the system is decreasing. So the entropy is also decreasing.
what is difference between vapourization and boiling point?
Answer:
Vaporization is basically just evaporation which does not require nearly as much heat and happens naturally however when it comes to boiling point this is the point where water has been heated enough to start bubbling and changing state slowly.
Explanation:
In the reaction MgCl2 + 2KOH → Mg(OH)2 + 2KCI, how many grams of KOH
react with 1 mole of MgCl2?
A. 95 g
B. 56 g
C. (1/2)(56 g)
O D. (2)(56 g)
Answer:
The correct option is;
D. (2)(56 g)
Explanation:
MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl
From the balanced chemical reaction equation, we have;
One mole of MgCl₂ reacts with two moles of KOH to produce one mole of Mg(OH)₂ and 2 moles of KCl
Therefore, the number of moles of KOH that react with one mole of KCl = 2 moles
The mass, m, of the two moles of KOH = Number of moles of KOH × Molar mass of KOH
The molar mass of KOH = 56.1056 g/mol
∴ The mass, m, of the two moles of KOH = 2 moles × 56.1056 g/mol = 112.2112 grams
The amount in grams of KOH that react with one mole of MgCl₂ = 112.2112 grams ≈ 112 grams = (2)(56 g).
Answer:
the answer is D
Explanation:
good luck
Epinephrine (adrenaline) is a hormone secreted into the bloodstream in times of stress. It contains 59.0% C, 7.15% H, 26.20% O, and 7.65% N and has a molar mass of 183 g/mol. What is its molecular formula
Answer:
C9H13O3N
Explanation:
Take the atomic mass of C=12.0, H=1.0, O=16.0 and N=14.0.
We can draw a chart (please view this on desktop so to avoid spacing errors):
Let the mass of Epinephrine be 100g.
C H O N
mass(g) : 59 7.15 26.2 7.65
no. of moles : 59/12 =4.9167 7.15/1 = 7.15 26.2/16=1.6375 7.65/14=0.5464
(n.o.m. = mass/molar mass)
Ratio: 4.9167/0.5464 =9 7.15/0.5464=13 1.6375= 3 0.5464/0.5464 =1
(divide the n.o.m. by the smallest n.o.m., which is 0.5464 in this case, take the whole numbers)
So, the empirical formula will be: C9H13O3N
But this is still not yet the molecular formula. We have to ensure the molar mass is 183g/mol. Multiply the empirical formula by n.
So, let the molecular formula of Epinephrine be (C9H13O3N)n.
12x9n + 1x13n + 16x3n + 14n = 183
108n + 13n + 48n + 14n = 183
183 n = 183.
n = 1
Hence, the molecular formula is C9H13O3N.
The structures found in a living cell can be compared to the parts of a factory that produces cars. Which part of the factory is most similar to the nucleus of a living cell? *
The computers that help control the machines in the factory
Which scenario would result in a decrease in population size, or a negative population growth? Use this formula: population growth = (birth rate + immigration) – (death rate + emigration) 0 individuals emigrate, 14 individuals die, 14 individuals are born, 14 individuals immigrate 40 individuals emigrate, 0 individuals die, 10 individuals are born, 28 individuals immigrate 12 individuals emigrate, 5 individuals die, 17 individuals are born, 0 individuals immigrate 19 individuals emigrate, 4 individuals die, 25 individuals are born, 0 individuals immigrate
Answer:
B) 40 individuals emigrate, 0 individuals die, 10 individuals are born, 28 individuals immigrate
Explanation:
its right on edg2020 :)
Which is the formula mass of Na2S04?
Answer:
The formula mass of Na2S04 is 142.04 g/mol
Answer:
142.04 g/mol
Explanation:
the formula Na2SO4 means:two moles sodium (45.98g), one mile sulfur (32.06g), and four moles oxygen (64.00g) combine to form one mole of sodium surface (142.04g).
Cuantos gramos de sulfato de plomo (II) se requieren para preparar 200mL una solución de esta sal a una concentración de 100 ppm. Si se toma una muestra de 30 mL de la disolución anterior y se diluye en 1000 mL de agua, ¿cuál es la concentración de la disolución?
Answer:
0.020g de sulfato de plomo se requieren
La concentración de la solución diluida es de 3ppm
Explanation:
Las partes por millón (ppm) son definidas como:
miligramos soluto / 1L solución.
Si deseas preparar una solución a 100ppm de sulfato de plomo (II) necesitas 100mg de este sulfato en 1L. En 200mL = 0.200L vas a necesitar:
0.200L × (100mg / 1L) = 20mg de sulfato de plomo (II).
Como 1000mg = 1g,
20mg × (1g / 1000mg) = 0.020g de sulfato de plomo se requieren.
Ahora, se van a tomar 30mL de esta solución y se diluirán a 1000mL. Se diluye la solución:
1000mL / 30mL = 33.33 veces.
Como la solución inicial es de 100ppm, esta dilución genera una solución de concentración:
100ppm / 33.33 = 3ppm
The formula for the compound ammonium chloride: NH4Cl+ NH4Cl NH3Cl NH4Cl2
Answer:
NH4Cl
Explanation:
i just did the test
Answer:
NH4Cl
Explanation:
Edg 2020