contestada

Solve the following problems and show the complete solutions.
1. How many moles of Carbon Dioxide is equivalent to 1.5X1023 atoms of CO2?
2. If you have 5grams of pure Aluminum, (Al), how many atoms does it have? (Al=27)\.
3. If 3 moles Sodium (Na) reacts with exact Chlorine gas (Cl2) in this reaction: 2Na + Cl2 ---> 2NaCl How many mole of Sodium Chloride (NaCl) will be produced?
4. Give the mass percent composition of Potassium, Sulfur and Oxygen in a molecule of Potassium Sulfate: K2SO4.(atomic mass: K=39, S=32).
5. If 162g of Aluminum reacts with 144g of Oxygen gas to form Aluminum oxide, what is the mass percentage of Aluminum?
6. A sample was analyzed and found to contain 40% Carbon. 6.71% Hydrogen and 53.29% Oxygen. If the molecular mass of this compound is 18.16g/mol, what is the empirical and molecular formula of this compound?

Relax

Respuesta :

pstnonsonjoku

The molecular formula of the compound is C6H12O6.

1) We know that;

1 mole of CO2 contains 6.02 X 10^23 atoms

x moles of CO2 contains 1.5 X 10^23 atoms

x = 1 mole X  1.5 X 10^23 atoms /6.02 X 10^23 atoms

x = 0.25  moles of CO2

2) 1 mole of pure Al has 27 g

x moles of Al has 5 g

x = 1 mole ×  5 g/ 27 g

x = 0.19 moles

If 1 mole of Al contains 6.02 X 10^23 atoms

0.19 moles of Al contains 0.19 moles  ×  6.02 X 10^23 atoms /1 mole

= 1.14 X 10^23 atoms

3) From 2Na + Cl2 ---> 2NaCl;

2 moles of Na produces 2 moles of NaCl hence 3 moles of Na will also produce 3 moles of NaCl.

4) The molar mass of K2SO4 is obtained from;

2(39) + 32 + 4(16) = 78 + 32 + 64 = 174 g/mol

Now;

Percentage by mass of K = 2(39)/ 174  ×  100/1 = 44.8%

Percentage by mass of S = 32/174 ×  100/1 = 18.4%

Percentage by mass of O = 4(16)/174 ×  100/1 = 36.8%

5) The reaction equation is;

4Al(s) + 3O2(g) ----> 2Al2O3

Total mass present =  162g + 144g = 306 g

Mass percent of Al =  162g/ 306 g ×  100/1 =52.9%

6)

C - 40/12     H -  6.71/1        O - 53.29/16

C - 3.33      H - 6.71            O - 3.33

Dividing through by the lowest ratio

C- 3.33/3.33     H - 6.71/3.33    O - 3.33/3.33

C - 1                  H - 2                 O - 1

The empirical formula is CH2O

Now;

[12 + 2(1) + 16] n = 180.16

30n = 180.16

n = 180.16/30

n = 6

The molecular formula is C6H12O6.

Learn more about molecular formula: https://brainly.com/question/11588623

Otras preguntas