Question 1

A 14.01 g sample of N$$_2$$ reacts completely with H$$_2 to $$form ammonia (NH$$_3). If $$ammonia is the only product, what mass, in grams, of ammonia is formed?

Accepted Answer

17.03 g

Question 2

Given the reaction: Fe$$_2O$_3(s) + 2 Al(s$$) $$\rightarrow Al$_2O$_3(s) + 2 Fe(s$$), what is the percent yield if 28.65 g of Fe is produced from 50.00 g of Fe$$_2O$_3$$ with excess Al?

Accepted Answer

81.93%

Question 3

Determine the molarity of a solution formed by dissolving 3.00 moles of NaCl in enough water to yield 4.00 L of solution.

Accepted Answer

$$0.750\,\mathrm{M}$$

Question 4

According to the reaction: 2 KCl(aq) + Pb(NO$$_3$$)$$_2(aq$$) $$\rightarrow$$ PbCl$$_2(s) + 2 $$KNO$$_3(aq$$), what volume of 0.244 M KCl solution is required to react exactly with 50.0 mL of 0.210 M Pb(NO$$_3$$)$$_2$$ solution?

Accepted Answer

86.1 mL

Question 5

What is the quantity (in mL) of a 6.00 M Na$$_2CO$_3$$ stock solution necessary to create 750.0 mL of a 1.50 M Na$$_2CO$_3$$ solution?

Accepted Answer

188 mL

Question 6

What element(s) is/are undergoing oxidation (if any) in the following reaction? CH$$_4(g) + 2 O$_2(g$$) $$\rightarrow CO$_2(g) + 2 H$_2O(g)$$

Accepted Answer

C

Question 7

If the percent yield for the following reaction is 75.0%, and 35.0 g of NO$$_2$$ are consumed in the reaction, how many grams of nitric acid, HNO$$_3(aq$$), are produced? 3 NO$$_2(g) + H$_2O(l$$) $$\rightarrow 2 $$HNO$$_3(aq) + NO(g)$$

Accepted Answer

24.0 g

Question 8

Consider the following balanced reaction. What mass (g) of CO$$_2$$ can be formed from 288 mg of O$$_2$$? Assume that there is excess C$$_3H$_8SH $$present. C$$_3H$_8SH(l) + 6 O$_2(g$$) $$\rightarrow 3 CO$_2(g) + SO$_2(g) + 4 H$_2O(g)$$

Accepted Answer

0.396 g CO$$_2$$

Question 9

What volume of 0.305 M AgNO$$_3 is $$required to react exactly with 155.0 mL of 0.274 M Na$$_2SO$_4$$ solution?

Accepted Answer

278 mL

Question 10

Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Na$$_2CO$_3$$ and HCl are mixed.

Accepted Answer

$$\mathrm{CO}_3$$^{2-}$$(aq) + 2 H^+(aq) \rightarrow H_2CO_3(aq)$$

Question 11

Define pressure.

Accepted Answer

Force exerted per unit area by gas particles as they strike the surfaces around them.

Question 12

What pressure will 14.0 g of CO exert in a 3.5 L container at 75$$^\circC$$?

Accepted Answer

$$5.0\,\mathrm{atm}$$

Question 13

A 0.334 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm. What is the identity of the halogen?

Accepted Answer

Cl$$_2$$

Question 14

What pressure would a gas mixture in a 10.0 L tank exert if it were composed of 48.5 g He and 94.6 g CO$$_2 at 398 K$$?

Accepted Answer

$$46.6\,\mathrm{atm}$$

Question 15

Determine the theoretical yield and the percent yield if 21.8 g of K$$_2CO$_3 is $$produced from reacting 27.9 g KO$$_2$$ with 29.0 L of CO$$_2 (at $$STP) according to: 4 KO$$_2(s) + 2 CO$_2(g$$) $$\rightarrow 2 K$_2CO$_3(s) + 3 O$_2(g)$$

Accepted Answer

61.0 g, 35.7% yield

Question 16

Which of the following signs on $$q$$ and $$w$$ represent the surroundings that is doing work on the system, as well as gaining heat from the surroundings?

Accepted Answer

$$q = +$$, $$w = +$$

Question 17

Determine the final temperature of a gold nugget (mass = 376 g) that starts at 398 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J/g·°C.

Accepted Answer

377 K

Question 18

Calculate the change in internal energy ($$\Delta E) $$for a system that is giving off 25.0 kJ of heat and is changing from 12.0 L to 6.00 L in volume at 1.50 atm pressure. (Remember that 101.3 J = 1 L·atm)

Accepted Answer

$$-24.1\,\mathrm{kJ}$$

Question 19

A 6.55 g sample of aniline (C$$_6H$_5NH$_2$$, molar mass = 93.13 g/mol) was combusted in a bomb calorimeter. If the temperature rose by 32.9$$^\circC$$, use the information below to determine the heat capacity of the calorimeter. $$\Delta H_{rxn} = -1.28 	imes 10^4$ kJ for 4 mol aniline.

Accepted Answer

6.84 kJ/$$^\circC$$

Question 20

An endothermic reaction has

Accepted Answer

A positive $$\Delta H$$, absorbs heat from the surroundings, and feels cold to the touch.

General Chemistry Practice Quiz: Stoichiometry, Solutions, Gases, Thermochemistry, and Calorimetry

Guida di studio - Domande di pratica

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