How to do an equation

Why is a homogeneous mixture not considered a pure substance? Question 6 options: A pure substance can be separated by physical

krok68 [10]

1. Why is a homogeneous mixture not considered a pure substance?

Answer:

A pure substance can be separated by chemical means, while a mixture can be separated by physical means.

2. What is true if mass is conserved in a reaction?

Answer:

There are equal numbers of atoms on both sides.

3. Methane reacts with oxygen then what are the products?

Answer:

carbon dioxide and water

4. Which one of the following is not a homogeneous mixture?

Answer:

vegetable soup

5. The substance is not uniform in appearance and each part of the mixture contains a combination of different ingredients in different ratios.

Answer:

heterogeneous mixtures

6. If a solution is saturated, which of these is true?

Answer:

More solvent can be dissolved

7. Which of these substances are molecules?

Answer:

All compounds are molecules but not all molecules are compounds. Molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element. So correct option is 3 and 4.

8. What makes a solution a homogeneous mixture?

Answer:

It is uniform in composition.

9. When a solute is added to a solution, why does it remain homogeneous?

Answer:

The solute dissolves.

10. The chemical formula of glucose is C6H12O6, so it is classified as a(n)

Answer:

pure substance.

11. How many chlorine (Cl) atoms would be in 4 molecules of salt (4 NaCl)?

Answer:

4

12. In a solution of salt and water, which component is the solute?

Answer:

Salt

13. These substances are all H2O2, Li , NaCl , O2

Answer:

Pure Substances

14. If you have 5 grams of product after a chemical reaction, how many grams of reactants did you have at the start of the reaction?

Answer:

5

15. What is the difference between a compound and a mixture?

Answer:

A compound is a pure substance, but a mixture is not.

16. A firework exploding would be an example of a(n) ________.

Answer:

Exothermic reaction

17. If Lavoisier heated 100 grams of powdered mercuric oxide to produce 93 grams of liquid mercury, how much oxygen would be released?

Solution

2HgO ==> 2Hg + O2

Mass of HgO = 100 g

Molar mass of HgO = 216.59 g/mol

Moles = mass/molar mass = 0.46 moles

From balance chemcial equation

HgO : O2

2 = 1

0.46 = (1 × 0.46 ) ÷ 2 = 0.23 moles

mass of O2 = moles× molar mass = 0.23 × 32 = 7.36 g

18. Using the Law of Conservation of Matter, determine the number of grams of iron sulfide (FeS) that will be produced in this reaction.

Solution

12g Fe + 64g S → _____ g FeS

According to Law of Conservation of Matter, The total mass of reactant is equal to total mass of product , so the number of grams of iron sulfide (FeS) that will be produced in this reaction as follow.

12 + 64 = 76 g of FeS

Hope this Help.

3 0

3 years ago

Read 2 more answers

6

Butoxors [25]

Answer:

the 6 stands for the atomic number

the 12.01 stands for the atomic mass

6 0

2 years ago

Nitrogen gas is being withdrawn at the rate of 4.5 g/s from a 0.15-m3 cylinder, initially containing the gas at a pressure of 10

faust18 [17]

Answer:

Final temperature = 152.57K,

Pressure = 0.6907 bar.

dT/dt = - 1,151 K/s.

Explanation:

The first thing to do here is to write out the equation for mass balance as given below:

dN/dt = N -------------------------------------------------------------------------------------------(1).

N = P/T, then, substitute the values given in the question into:

d[p/T]/ dt = [- 4.5/28 × 8.314]/0.15 = - 8.9 × 10⁻⁵ bar/K.s.

Thus, there is the need to integrate, Integrate [p/T]f = 10/320 - 8.9 × 10⁻⁵ bar/K.s. ------------------------------------(2).

NB; fT = final temperature, fP = final pressure and iT = initial temperature.

Also, [ fT]³⁰/₈.₃₁₄/ [fP] = [iT]³⁰/₈.₃₁₄/ Pi] = [ 320]³⁰/₈.₃₁₄/ 10.

Therefore, [fT]³⁰/₈.₃₁₄ = 109.52 × 10⁶.

Final temperature= [fP]³⁰/₈.₃₁₄ × 169.05.

Note that fP/ [fP]³⁰/₈.₃₁₄ × 169.05 = 10/320 - 8.9 × 10⁻⁵.

Therefore, [fP]¹ ⁻ ³⁰/₈.₃₁₄ = 0.7651.

Hence, Final temperature = 152.57K,

Pressure = 0.6907 bar

dT/ dt = N[RT]² / Cv . PV.

R = 30 - 8.314 = 21.86 J/mol K.

Then, the rate of change of the gas temperature at this time = dT/dt = - 1,151 K/s.

4 0

2 years ago

Convert 5795 grams into pounds.

Rama09 [41]

Answer:

12.776 pounds

Explanation:

hope this helps:)

3 0

2 years ago

For which of the following reactions are both reactants and products likely to be found when the reaction appears to be complete

Scorpion4ik [409]

The answer is
HF + H2O <--> H3O(+) + F(-)

HF + H2O gives H3O(+) + F(-)
and 
H3O(+) + F(-) gives HF + H2O
it is a reciprocal reacation, so 
reactions are both reactants and products

6 0

3 years ago