Mastering Chemistry Chapter 7 Quiz

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s)+O2(g)→2MgO(s) When 2.50 g of magnesium burns, the theoretical yield of magnesium oxide is ________ g.

4.15

Now that we have put coefficients of 3 in front of CaSO4 and CaCl2, what coefficient should go in front of AlCl3 to balance both the Cl atoms and the Al atoms? 3CaSO4+?AlCl3→3CaCl2+Al2(SO4)3 Express your answer numerically as an integer.

2

Notice that "SO4" appears in two different places in this chemical equation. SO42− is a polyatomic ion called "sulfate." What number should be placed in front of CaSO4 to give the same total number of sulfate ions on each side of the equation? ?CaSO4+AlCl3→CaCl2+Al2(SO4)3 Express your answer numerically as an integer.

3

Now that we have put a coefficient of 3 in front of CaSO4, what coefficient should go in front of CaCl2 to balance calcium (Ca)? 3CaSO4+AlCl3→?CaCl2+Al2(SO4)3 Express your answer numerically as an integer.

3

In a chemical reaction, what is the the theoretical yield? The percent yield? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

The theoretical yield is the amount of product that can be made in a chemical reaction based on the amount of LIMITING REACTANT. The percent yield is calculated as the ratio of the ACTUAL YIELD to the THEORETICAL YIELD.

What is the correct sequence of coefficients when this equation is balanced? ___CS2(l) + ___O2(g) → ___CO2(g) + ___SO2(g)

1, 3, 1, 2

In a chemical reaction, what is the limiting reactant? What do we mean when we say a reactant is in excess? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

1. The LIMITING REACTANT is the reactant that is completely consumed in a chemical reaction. 2. The REACTANT IN EXCESS is any reactant that occurs in a quantity greater than that is required to completely react with the LIMITING REACTANT. 3. The amount of product can be calculated based on the amount of LIMITING REACTANT.

Which of the following contains the most atoms? You shouldn't need to do a calculation here. 10.0 g Al 10.0 g He 10.0 g Kr 10.0 g Cs 10.0 g Ca

10.0 g He

Consider the following reaction. How many moles of oxygen are required to produce 8.00 moles of water? Assume that there is excess C3H7SH present. C3H7SH(l) + 6 O2(g) →→ 3 CO2(g) + SO2(g) + 4 H2O(g)

12.0 moles O2

Give the theoretical yield, in moles, of CO2 from the reaction of 4.00 moles of C8H18 with 4.00 moles of O2. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

2.56 moles

According to the following balanced reaction, how many moles of NO are formed from 8.44 moles of NO2 if there is plenty of water present? 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

2.82 moles NO

Calculate the mass percent composition of sulfur in Al2(SO4)3.

28.12 %

Calculate the molar mass of H2CO3.

62.03 g/mol

Which one of the following is not an empirical formula? C2H4O CH2O C2H6O2 CHO

C2H6O2