Q: Which of the following pairs of reactants will result in a precipitation reaction?

$\text{Na}_2\text{SO}_4(aq) + \text{Ba(NO}_3)_2(aq)$

Question 1

Which of the following gases is NOT a major contributor to global warming?

Accepted Answer

Argon

Question 2

According to the balanced reaction $3 	ext{NO}_2(g) + 	ext{H}_2	ext{O}(l) ightarrow 2 	ext{HNO}_3(aq) + 	ext{NO}(g)$, how many moles of $	ext{HNO}_3$ are formed from 3.75 moles of $	ext{NO}_2$ if there is plenty of water present?

Accepted Answer

$2.50$ mol

Question 3

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: $2 	ext{Mg}(s) + 	ext{O}_2(g) ightarrow 2 	ext{MgO}(s)$. When 5.00 g of magnesium burns, the theoretical yield of magnesium oxide is:

Accepted Answer

$8.29$ g

Question 4

Strontium phosphate reacts with sulfuric acid to form strontium sulfate and phosphoric acid. What is the coefficient for sulfuric acid when the equation is balanced using the lowest, whole-numbered coefficients?

Accepted Answer

$2$

Question 5

Silicon dioxide is heated to melting, it reacts with solid carbon to form liquid silicon and carbon monoxide gas. In an industrial preparation of silicon, $145.6$ kg of $	ext{SiO}_2$ reacts with $65.9$ kg of carbon. If the percent yield of silicon is $95.7\%$, what is the limiting reactant and the theoretical yield (in kg) of silicon?

Accepted Answer

Limiting reactant: SiO$_2$; Theoretical yield: $68.7$ kg

Question 6

If a reaction mixture initially contains $24.18$ g of $	ext{KClO}_3$ and $17.6$ g of $	ext{CO}_2$, what mass (in g) of excess reactant is left if the reaction is allowed to go to completion? $2 	ext{KClO}_3(s) + 3 	ext{CO}_2(g) ightarrow 2 	ext{KCl}(s) + 3 	ext{CO}_2(g) + 3 	ext{O}_2(g)$

Accepted Answer

$19.53$ g $	ext{KClO}_3$

Question 7

Sulfuric acid dissolves aluminum metal according to the reaction: $2 	ext{Al}(s) + 3 	ext{H}_2	ext{SO}_4(aq) ightarrow 	ext{Al}_2(	ext{SO}_4)_3(aq) + 3 	ext{H}_2(g)$. Suppose you want to dissolve an aluminum block with a mass of $21.2$ g. What minimum mass of $	ext{H}_2	ext{SO}_4$ (in g) do you need?

Accepted Answer

$116$ g

Question 8

Determine the molarity of a solution formed by dissolving $468$ mg of $	ext{MgI}_2$ in enough water to yield $50.0$ mL of solution.

Accepted Answer

$0.0936$ M

Question 9

What volume of $0.305$ M $	ext{AgNO}_3$ is required to react exactly with $155.0$ mL of $0.274$ M $	ext{Na}_2	ext{SO}_4$ solution? (Hint: You will want to write a balanced reaction.)

Accepted Answer

$278$ mL

Question 10

Which of the following is considered a STRONG electrolyte?

Accepted Answer

$	ext{H}_2	ext{SO}_4$

Question 11

Which of the following pairs of reactants will result in a precipitation reaction?

Accepted Answer

$	ext{Na}_2	ext{SO}_4(aq) + 	ext{Ba(NO}_3)_2(aq)$

Question 12

The titration of $50.0$ mL of an unknown concentration $	ext{H}_3	ext{PO}_4$ solution requires $126$ mL of $0.218$ M $	ext{KOH}$ solution. What is the concentration of the $	ext{H}_3	ext{PO}_4$ solution (in M)?

Accepted Answer

$0.114$ M

Question 13

Lead(II) ions can be precipitated from aqueous solutions by the addition of aqueous iodide: $	ext{Pb}^{2+}(aq) + 2 	ext{I}^-(aq) ightarrow 	ext{PbI}_2(s)$. Lead iodide is virtually insoluble in water so that the reaction appears to go to completion. How many milliliters of $1.500$ M $	ext{HI}$ must be added to a solution containing $0.600$ g of $	ext{Pb(NO}_3)_2$ to completely precipitate the lead?

Accepted Answer

$8.00$ mL

Question 14

A sample of an unknown compound occupies $245$ mL at $298$ K and $1.26$ atm. What is the molar mass of the unknown compound?

Accepted Answer

$131$ g/mol

Question 15

A sample of $	ext{N}_2$ effuses in $16.0$ s. How long will the same size sample of $	ext{Cl}_2$ take to effuse?

Accepted Answer

$21.5$ s

Question 16

Zinc reacts with aqueous sulfuric acid to form hydrogen gas: $	ext{Zn}(s) + 	ext{H}_2	ext{SO}_4(aq) ightarrow 	ext{ZnSO}_4(aq) + 	ext{H}_2(g)$. In an experiment, $225$ mL of wet $	ext{H}_2$ is collected over water at $27^{\circ}$C and a barometric pressure of $785$ torr. The vapor pressure of water at $27^{\circ}$C is $26.74$ torr. The partial pressure of hydrogen in this experiment is ____ atm.

Accepted Answer

$0.993$ atm

Question 17

A balloon contains $0.76$ mol $	ext{H}_2$, $0.18$ mol Ne, $0.011$ mol Rn and $0.026$ mol Cl$_2$ at $739$ mm Hg. What is the partial pressure of Ne?

Accepted Answer

$130$ mm Hg

Question 18

Calculate the root mean square velocity of argon atoms at $25^{\circ}$C. ($M = 39.95$ g/mol)

Accepted Answer

$515$ m/s

Question 19

Using the graph below, determine the gas that has the highest density at STP.

Accepted Answer

Curve D

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