Answer:
B. choosing a material that will show warning before it fails.
Explanation:
Answer:
APEX
Explanation:
B
Indicators change color when an acid and a base are mixed together. The change in color most likely indicates that a chemical change has occured. a physical change has occured. a new acid has been produced. a new base has been produced.
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
A 2.5-liter sample of a gas has 0.30 mole of the gas. If 0.15 mole of the gas is added, what is the final volume of the gas? Temperature and pressure remain constant. 3.4 liters 3.8 liters 4.2 liters 4.7 liters
Answer:
3.75 ltrs
Explanation:
The final volume of the gas is 3.8L.
What is volume?Volume is the quantity of space occupied by a liquid, solid, or gas.
Using Avogadro's law.
Avogadro's Law:
According to Avogadro's law an equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant.V₁/n₁=V₂/n₂
Where V₁ = initial volume
V₂ = final volume
n₁ = initial amount of gas in moles
n₂ = final amount of gas in moles
Avogadro's Law explains when the temperature and pressure are kept constant, volume is directly proportional to gas amount in moles, which means when the volume increases, the amount of gas also increases.
V ∝ n
V₁/n₁ = V₂/n₂
V₁ = 2.5L, V₂ = ?, n₁ = 0.30 mol, n₂ = 0.45 mol
substituting the above values in the equation,
2.5L/0.30 mol = V₂/0.45 mol
V₂ = 1.125/0.30 mol
V₂ = 3.8L
Hence, 3.8L is the final volume of the gas.
To learn more about Avogadro's law here
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Select the correct answer.
What is the reason for heat transfer from one substance to another
Answer:
Difference in temperature.
Explanation:
Conduction is the movement of heat energy through a substance or from one substance to another by direct contact of atoms and molecules. Heat moves directly from one molecule to another. The heat energy speeds up the movement of the atoms and they collide with other molecules setting them into faster motion.
4. How much force, in g cm / s2 , is exerted by a golf ball described in problem 2 striking a tree while accelerating at 20 cm / s2 ? Show how you can solve this problem without knowing that F = m a. Explain your solution.
Answer:
Explanation:ifk
How does increasing temperature increase the number of reactions
Answer:
A
Explanation:
the increase in the temperature let's the particles to collide more so it increases the rate of reaction.
Answer:
I think the answer is option A.
Explanation:
Because when the temperature increases, the kinetic enegry increases which creates the effective collisions which lets the chemical to react.
Hope it helps..
Why is it incorrect to refer to a molecule of sodium chloride? a. Because sodium and chloride are not bonded together in any way. b. Because ionic compounds do not exist in discrete molecules--they exist in crystal lattices. c. Because molecules are not a meaningful term in chemistry. d. Because sodium chloride is not a compound found in nature.
Answer:
B. Because ionic compounds do not exist in discrete molecules -- they exist in crystal lattices.
Explanation:
A property of ionic compounds is that they form crystal lattice structures. Ionic compounds are crystals of many cations and anions bonded together. There is no molecule of ionic compounds because there is no single unit of the compound.
Hope this helps.
Research on ‘where a person’s carbon emissions come from inside a home’ and represent the data in the form of a pie chart. Pls answer with pie chart I WILL MARK U AS BRAINSLIEST IF YOU GIVE RIGHT ANSWER
Answer:
Here's what I get from one source.
Explanation:
[tex]\begin{array}{lc}\textbf{Source} &\textbf{Contribution \%} \\\text{Space heating }& 45\\\text{Water heating} &18\\\text{Space cooling} & 9 \\\text{Computers/Electronics} & 6 \\\text{Lighting} & 6 \\\text{Cooking} & 4 \\\text{Refrigeration} & 4 \\\text{Wet cleaning} & 3 \\\text{Other} & 5 \\\end{array}[/tex]
The pie chart is in the Figure below.
What's the valency of sulphur for Na2SO3
Explanation:
What are the two oxidation states of sulphur in sodium thiosulphate ? In thiosulphate, two sulphurs have oxidation state of -2 and +6. (as per suggestions). Sulphur bonded to three oxygen is considered to have +6 (Sulphur A) and other sulphur has -2 (Sulphur B).
Marking BRAINLIEST!! - Chlorine reacts with methane to form gaseous hydrogen chloride and chloromethane according to the following equation: Cl2 (g) + CH4 (g) → HCl (g) + CH3Cl (g) If 100 mL of chlorine reacted with excess methane at constant pressure and temperature, what volume of chloromethane would be formed?
Answer:
the answer for the question is 40 mL
Aspirin (C9H8O4) is an acid which can be titrated with a base to determine purity. If an aspirin tablet weighing 0.615 g is titrated with standardized 0.1121 M KOH, the endpoint is reached after 20.52 mL of KOH have been added. What is the percentage of aspirin in the tablet
Answer:
67.4 % of C₉H₈O₄
Explanation:
To make titrations problems we know, that in the endpoint:
mmoles of acid = mmoles of base
mmoles = M . volume so:
mmoles of acid = 20.52 mL . 0.1121 M
mmoles of acid = mg of acid / PM (mg /mmoles)
Let's determine the PM of aspirin:
12.017 g/m . 9 + 1.00078 g/m . 8 + 15.9994 g/m . 4 = 180.1568 mg/mmol
mass (mg) = (20.52 mL . 0.1121 M) . 180.1568 mg/mmol
mass (mg) = 414.4 mg
We convert the mass to g → 414.4 mg . 1g / 1000mg = 0.4144 g
We determine the % → (0.4144 g / 0.615 g) . 100 = 67.4 %
A microwave oven produces energy waves which are: A. longer than visible light B. shorter than visible light C. not part of the electromagnetic spectrum
Answer:
The answer is option A.
longer than visible light
Hope this helps you
Answer:
electromagnatic waves
Explanation:
what’s the reaction type of aqueous magnesium sulfate + aqueous sodium carbonate?
Answer: Double displacement reaction
Explanation:
Double displacement reaction is defined as the reaction where exchange of ions takes place.
The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The chemical reaction between aqueous magnesium sulfate and aqueous sodium carbonate is represented as:
[tex]MgSO_4(aq)+Na_2CO_3(aq)\rightarrow Na_2SO_4(aq)+MgCO_3(s)[/tex]
An ionic bond is the attraction between _____.
Answer:
oppositely charged ions in a chemical compound
Explanation:
Answer:
Between ions
Explanation:
If the compound beryllium chloride (BeCly) has no lone pairs, it would take which shape?
A. Trigonal blpyramid
B. Octahedral
OC. Trigonal planar compound
D. Linear compound
Answer:
Liner shape
Explanation:
Because BeCl2 has 2 bond pair and no lone pair it means it will have liner shape and 180 degree angle.
Answer:
liner compound
Explanation:
Answer the following questions:
1. Define a compound. State three points of evidence to show that sodium chloride is a compound.
2. When Iron powder and Sulphur powder were mixed together and heated strongly, a substance A was formed. When did. Hydrochloric acid was added to substance A, the gas B was evolved.
a) What is A and what type of substance is it?
b) Name the gas B. State one characteristic property of gas B.
c)Is the reaction of Iron and Sulphur powder a chemical change or a physical change.
Answer the question according to the class 9th student.
Answer:
1. A compound is a group of elements that cannot be separated by physical methods.
NaCl is a compound becuse it cannot be separated by physical methods.
It consists of postive and negative ions.
It can be separated only by chemical reactions.
2. (a) A is a mixture of iron and sulphur and it is in liq form.
(b) Gas B is hydrogen gas and it has sharp pungent irritating smell.
(c) It is a physical change.
Explanation:
What is the [tex]K_{c}[/tex] Expression for the following reaction [tex]C_{6}H_{12}O_{6} + O_{2} \ \ - \ \ \textgreater \ 6H_{2}O+6CO_{2}[/tex] NO ABSURD ANSWERS!
Answer:
[tex]\boxed{\mathrm{view \: explanation}}[/tex]
Explanation:
This is an irreversible reaction, we cannot derive any [tex]\mathrm{K_c}[/tex] expression for it. The [tex]\mathrm{K_c}[/tex] expression can only be derived for reversible reactions and not irreversible reactions. We cannot derive the [tex]\mathrm{K_c}[/tex] expression for this reaction.
What substance does a neutral substance release?
Answer:
Neutral substance is a substance that show no acid or base properties.
Explanation:
Neutral substance is a substances that show no acid or base properties, has an equal number of hydrogen and hydroxyl ions and does not change the color of litmus paper.
Answer:
They release no substance
Explanation:
Since the substance is neutral, nothing will be released from it.
Given the wavelength of the corresponding emission line, calculate the equivalent radiated energy from n = 4 to n = 2 in both joules and electron volts. Also, calculate the frequency of the wave. λ (Á) = 4861, ƒ(Hz), E(J), E(eV)
Explanation:
It is given that,
Initial orbit of electrons, [tex]n_i=4[/tex]
Final orbit of electrons, [tex]n_f=2[/tex]
We need to find energy, wavelength and frequency of the wave.
When atom make transition from one orbit to another, the energy of wave is given by :
[tex]E=-13.6(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2})[/tex]
Putting all the values we get :
[tex]E=-13.6(\dfrac{1}{(4)^2}-\dfrac{1}{(2)^2})\\\\E=2.55\ eV[/tex]
We know that : [tex]1\ eV=1.6\times 10^{-19}\ J[/tex]
So,
[tex]E=2.55\times 1.6\times 10^{-19}\\\\E=4.08\times 10^{-19}\ J[/tex]
Energy of wave in terms of frequency is given by :
[tex]E=hf[/tex]
[tex]f=\dfrac{E}{h}\\\\f=\dfrac{4.08\times 10^{-19}}{6.63\times 10^{-34}}\\\\f=6.14\times 10^{14}\ Hz[/tex]
Also, [tex]c=f\lambda[/tex]
[tex]\lambda[/tex] is wavelength
So,
[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{6.14\times 10^{14}}\\\\\lambda=4.88\times 10^{-7}\ m\\\\\lambda=488\ nm[/tex]
Hence, this is the required solution.
f(Hz) = 6.17 × 10¹⁴
E(J) = 4.09 × 10⁻¹⁹
E(ev) = 2.56
Flask is immersed in a large beaker of very hot water. At first, the level of the liquid in the tube falls, but after a short time it rises. Explain why the liquid level in the tube stops falling and starts to rise.
Answer:
Explanation:
When a flask is dipped in very hot water in a large beaker , the flask expands due to heat gain . As a result , level of water in tube fitted in flask goes down .
After some time , the water inside tube also become hot so it expands . coefficient of volume expansion of water is more than coefficient of volume expansion of glass . Hence greater expansion takes place in the volume of water . It is due to this fact that water level in tube starts rising after some time of fall .
Give the word equation for the reaction between hydrogen and oxygen
Answer:
Hydrogen gas (H₂) + Oxygen gas (O₂) → Water (H₂O)
Explanation:
Hydrogen reacts with oxygen to form water. The reactants are hydrogen and oxygen and the product is water.
Answer:
Word Equation:
Hydrogen + Oxygen = Water
Hydrogen gas reacts with Oxygen gas to give Water.
The chemical Reaction is as follows:
[tex]2H_{2} + O_{2}[/tex] => [tex]2H_{2}O[/tex]
Each of the continents moves at a different rate and in a different direction. Based on this observation, do you believe that any of the modern continents will recombine to form a new supercontinent in the future? Why or why not?
Answer:
Supercontinent is a single landmass formed by the combination of many Earth's continental blocks or cratons.
Supercontinents form and split up every 400 or 500 million years and the last supercontinent was formed 300 million years ago, so it is possible that any of the modern continents will combine together to form a new supercontinent in future.
Answer:
Yes, modern continents could recombine to form a new supercontinent. Because the continents move at different rates and in different directions, it’s likely that in the future, continents will collide and join together.
Explanation: Edmentum's EXACT ANSWER SO DO NOT COPY! Rewrite it in your own words.
How much heat is needed to raise the temperature of water with mass of 27.0 g at 20.0°C to 45.0°C?
Answer:
2835 J
Explanation:
Take the specific heat capacity of water as 4.2 J/ g°C.
Energy (heat) = mass x specific heat capacity x change in temperature
(E= mcΔT)
E = 27 x 4.2 x (45-20)
E = 2835 J
Two oxides of lead were separately reduced to metallic lead by heating in a current of
i) Mass of yellow oxide taken=3.45g
ii) Mass of brown oxide taken=1.227g
Loss in mass during reduction=16g
Show that the above data illustrate the law of multiple proportions.
Answer:
HeyA ❤
Let us consider the mass of oxygen as 1 g.
Mass of lead obtained from yellow oxide = 3.45 g – 0.24 g = 3.21 g
Mass of oxygen = 0.24 g
The mass of lead that combines with 0.24 g of oxygen = 3.21 g
Therefore, mass of lead that combines with 1 g of oxygen = 3.21/ 0.24 = 13.4 g
Mass of lead obtained from brown oxide = 1.227 g – 0.16 g = 1.067
Mass of oxygen = 0.16g
The mass of lead that combines with 0.16 g of oxygen = 1.067 g
Therefore, mass of lead that combines with 1 g of oxygen = 1.067/ 0.16 = 6.66 g
Now, ratio of masses of lead which combines with a fixed mass of oxygen = 13.4 : 6.66
= 2 :1
Thus, masses of lead which combine with the fixed mass of oxygen are in the ratio of (2:1) i.e. small whole numbers.
Hence, the law of multiple proportions is illustrated.
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A sample of O2 gas is collected over water at 25oC at a barometric pressure of 751 torr. The vapor pressure of water at 25oC is 23.8 torr. What is the partial pressure of the O2 gas in the sample
Answer:
727.7 torr
Explanation:
Since the gas was collected over water, it is likely to be saturated with water vapour and the total pressure is given as;
Ptotal = Pgas + Pwater
From the question;
Ptotal = 751 torr
Pgas = ?
Pwater = 23.8 torr
Making Pgas subject of equation, we have;
Pgas = Ptotal - Pwater
Pgas = 751 torr - 23.8 torr
Pgas = 727.7 torr
Balancing Chemical Reactions Worksheet A glow stick is a popular toy and safety device. To use a glow stick, you bend a small flexible plastic tube to break a small glass capsule inside, at which point the stick begins to glow. How do you think this works
Answer:
Concept of chemi-fluorescence
Explanation:
A glow stick usually consists of two chemicals in a larger plastic tube: , a base catalyst (mostly sodium salicylate), and a suitable dye (sensitizer, or fluorophor). This creates an exergonic reaction when mixed together.
When a glow stick is bent, the flurophor which is a chemical that easily re-emits light upon excitation in smaller capsules is released into the other substance, there by causing it to emit radiation/light in the uv-visible region. The brightness and longevity of the glow stick is determined by varying the concentration of these chemicals.
I hope this explanation clarifies things.
Landfills are one source of CO2. As garbage decomposes, it releases CO2 into the air. Can you think of at least
one way that humans can reduce the amount of trash they dump in landfills?
Answer:
Recycling and reuse of materials
Explanation:
One of the greatest problems facing the human population is the problem of solid waste disposal. The menace of solid waste disposal has led to the idea of landfills. Land fills are depressions on the earth surface prepared for the purpose of solid waste disposal.
The most important approach towards solid waste disposal is the idea of recycling of materials. A material can be collected after use and processed into the same material or serve as a precursor in another manufacturing process. This means that no waste is generated as the materials which are supposed to be disposed of as solid waste are processed into other useful materials. This will reduce the volume of solid wastes generated that may need to be disposed in a landfill.
Answer:
There are many ways to reduce the amount of trash sent to landfills: Recycle as much as possible. Limit disposable products, and use reusable ones whenever possible. Reuse, sell, or pass along old items instead of throwing them away.
Explanation: PLATO
How many moles are in 10.23 g of PO4-3? How many moles are 8.25 x 10^28 molecules of Na2CO3? What is the mass of 6 moles of CH2O? How many formula units are in 6.34 g of NaCl? How many ions are in 0.25 moles of Cu+2? How many grams are in 3.4 x 10^24 molecules of CH4? How many moles are in 10 mL of water (density of water = 1 g/mL)? (sorry for so many questions in one)
Answer:
1) 0.1077 moles
2) 137043.2 moles
3) 180.186 grams
4) 6.53×10²² molecules or formula units
5) 1.505×10²³ ions
6) 90.626 grams
7) 0.555 moles
Explanation:
1) The number of moles, n = Mass of the substance/(Molar mass of the substance)
The molar weight of PO₄⁻³ is 94.971 g/mol
The number of moles in 10.23 g of PO₄⁻³ is n =10.23/94.971 = 0.1077 moles
The number of moles in 10.23 g of PO₄⁻³ = 0.1077 moles
2) The number of molecules of Na₂CO₃ in one mole of Na₂CO₃ is given by the Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ molecules
Therefore, the number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ is found by determining how many Avogadro's number of molecules are in 8.25 × 10²⁸ molecules of Na₂CO₃ as follows;
The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = (8.25 × 10²⁸)/(6.02 × 10²³) = 137043.2 moles
The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = 137043.2 moles
3) The molar mass of CH₂O = 30.031 g/mol
Therefore, the mass of 6 of CH₂O = 6 moles × 30.031 g/mol = 180.186 grams
The mass of 6 of CH₂O = 180.186 grams
4) The molar mass of NaCl = 58.44 g/mol
The number of moles of NaCl in 6.34 g of NaCl 6.34/58.44 = 0.1085 moles
1 formula unit of NaCl = 1 molecule of NaCl
The number of molecules in one mole of a substance = [tex]N_A[/tex] = 6.02 × 10²³
Therefore, the number of molecules in 0.1085 moles of NaCl = 6.02 × 10^(23) × 0.1085 = 6.53×10²² molecules or formula units
5) The number of ions per mole of any substance is give by Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ ions,
The number of ions in 0.25 moles of Cu⁺² = 0.25×6.02 × 10²³ ions = 1.505×10²³ ions
The number of ions in 0.25 moles of Cu⁺² = 1.505×10²³ ions
6) The molar mass of CH₄ = 16.04 g/mol
The number of moles, n, in 3.4×10²⁴ = 3.4×10^(24)/(6.02×10^(23)) = 5.65 moles 5.65*16.04
The mass of 5.65 moles of CH₄ = 5.65 moles × 16.04 g/mol = 90.626 grams
The mass of 3.4×10²⁴ molecules of CH₄ = 90.626 grams
7) The density of water = 1 g/mL
The volume of the water 10 mL
The mass of the water = Volume × Density = 10 mL × 1 g/mL= 10 grams
The molar mass of water = 18.015 g/mol
The number of moles of water in 10 g of water = mass/(Molar mass) = 10/18.015 = 0.555 moles.
What is organic chemistry
Explanation:
Hi there!!!
The organic chemistry is a branch of chemistry which deals with the study of hydrocarbons compounds. organic chemistry deals with the study of structure, properties and reactivity of carbon compounds. It is a very broad area where more than 100000 organic compounds are studied.
Hope it helps..
How are the oxygen atoms balanced for redox equations in acidic solutions?
A. H20 and OH- are used to balance the oxygen atoms.
B. H+ ions from the acid form H20 with the oxygen.
C. Ht and OH are used to balance the oxygen atoms.
D. H20 and H* are used to balance the oxygen atoms.
Answer:
The answer is option D.
Explanation:
In balancing in acidic solutions, the oxygen is accounted for by adding a water molecule or H2O on the side that needs oxygen and 2H+ molecules for every H20 molecules placed on the other side of the equation.
The H+ and H2O molecules are in the ratio 2 : 1
Hope this helps you
When balancing redox reaction equations, H20 and H^+ are used to balance the oxygen atoms.
Redox reaction equations show reactions in which electrons were lost or gained in the process. If the redox reaction involves oxygen, it is common to balance the oxygen atoms using H20 and H^+.
For instance, the equation of the reduction of MnO4^- to Mn^+ is shown below; MnO4^-(aq) + 8H^+(aq) + 5e ----> Mn^2+(aq) + 4H2O(l). We can see that hydrogen ions and water were used to balance the four oxygen atoms.
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Un compuesto ZO2 tiene masa molar igual a 64. La masa atómica de Z debe ser: A . 6. C. 12. E. 32. B. 10. D. 24.
Answer:
32. Opcion E
Explanation:
ZO₂ podemos entenderlo como dióxido de Z
1 mol de ZO₂ contiene 1 mol de Z y 2 moles de O₂ por lo que si la masa molar es de 64 g/mol, podemos plantear lo siguiente
Masa de Z + 2 masa de O = 64 g/mol
Sabemos que la masa del oxígeno es 16 g/mol
x + 2. 16 g/mol = 64 g/mol
x = 64 - 32 → 32 g/mol
La masa atómica coincide con la masa molar, por lo tanto la masa atomica de Z es 32.
Considerando la definición de masa molar, la respuesta correcta es la opción E: La masa atómica de Z debe ser 32.
La masa molar es la masa de un mol de una sustancia, la cual puede ser un elemento o un compuesto, esto es, es la relación entre la cantidad de sustancia y su masa.
En otras palabras, la masa molar es la cantidad de masa que una sustancia contiene en un mol.
En la tabla periódica, se puede encontrar la masa molar de los elementos, también llamada masa atómica o peso atómico.
Para calcular la masa molar de un compuesto, también llamado masa o peso molecular, se debe sumar la masa molar de los elementos del compuesto multiplicado por su cantidad en el compuesto.
Entonces, en este caso, siendo la masa molar del oxígeno (O) 16, y la masa molar del compuesto ZO₂ 64, y denominando x a la masa molar de Z, entonces la masa molar del compuesto puede expresarse como:
x + 2×16= 64
Resolviendo:
x + 32= 64
x=64 -32
x=32
Finalmente, la respuesta correcta es la opción E: La masa atómica de Z debe ser 32.
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