Exam 2: Chapters 5,6,7,8
Exam 2
Total Points: 60
PART 1: Multiple Choice questions: Q 1-24. (2 point each)
1.Chemical reactions (equations) show the following
a. Reactants
b.Products
c. Physical state of each (gas or liquid or solid)
d.All of the above
2.The following is true for a mole
a. It is also known as Avagadro’s number
b.It contains 6.022 * 1023 molecules
c. It contains mass equivalent to molecular weight
d.All of the above are true
3.In balancing chemical equations, the coefficients are used to
a. Show number of moles
b.Show volume of each in liters
c. Show amount of each in grams
d.Show temperature at which the substance is stable
4.2H2 + O2 2H2O means that
a. 2 grams of H2 g and 1 gram of O2 gas combine to form 2 grams of
water.
b.2 moles of H2 g and 1 mole of O2 gas combine to form 2 moles of
water.
c. 2 grams of H2 g and 1 gram of O2 gas combine to form 2 moles of
water.
, d.2 molecules of H2 g and 1 molecule of O2 gas combine to form 2
molecules of water.
5.2H2 + O2 2H2O. In this equation, correct
method to calculate molecular mass of water is
a. 2[2(mass of hydrogen) + mass of oxygen]
b.2(mass of hydrogen gas) + mass of oxygen gas
c. 2(mass of hydrogen) + mass of oxygen
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