CHAPTER 19. QUANTITATIVE ASPECTS OF CHEMICAL CHANGE 19.4
Chapter 19 End of chapter exercises
1. Write only the word/term for each of the following descriptions:
a. the mass of one mole of a substance
b. the number of particles in one mole of a substance
2. 5 g of magnesium chloride is formed as the product of a chemical reaction.
Select thetruestatement from the answers below:
a. 0 , 08 moles of magnesium chloride are formed in the reaction
b. the number of atoms of Cl in the product is 0 , 6022 × 1023
c. the number of atoms of Mg is 0 , 05
d. the atomic ratio of Mg atoms to Cl atoms in the product is1 : 1
3. 2 moles of oxygen gas react with hydrogen. What is the mass of oxygen
in the reactants?
a. 32 g
b. 0 , 125 g
c. 64 g
d. 0 , 063 g
4. In the compound potassium sulphate (K 2 SO 4 ), oxygen makes upx%of
the mass of the compound. x =?
a. 36 , 8
b. 9 , 2
c. 4
d. 18 , 3
5. The concentration of a 150 cm^3 solution, containing 5 g of NaCl is:
a. 0 , 09 mol·dm−^3
b. 5 , 7 × 10 −^4 mol·dm−^3
c. 0 , 57 mol·dm−^3
d. 0 , 03 mol·dm−^3
6. Calculate the number of moles in:
a. 5 g of methane (CH 4 )
b. 3 , 4 g of hydrochloric acid
c. 6,2 g of potassium permanganate (KMnO 4 )
d. 4 g of neon
e. 9 , 6 kg of titanium tetrachloride (TiCl 4 )
7. Calculate the mass of:
a. 0 , 2 mol of potassium hydroxide (KOH)
b. 0 , 47 mol of nitrogen dioxideChemistry: Chemical change 361