Section or time
Avogadro's Number \( =6.022 \times 10^{23}, \mathrm{R}=0.0821 \mathrm{~atm} \mathrm{~L} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}, 1 \mathrm{~atm}=101325 \mathrm{~Pa}=760 \mathrm{mmHg} \) (torr)
Q1) Circle the best answer: (fill the answer in the table in page 4) ( 36 marks, 1.5 each)
1) Which of the following are incorrectly paired?
A) Sr , alkaline earth metal
C) Na , transition metal
B) Ta , transition metal
D) F, halogen
2) When Balance the following equation to the smallest whole number: \( \mathrm{C}_{3} \mathrm{H}_{7} \mathrm{OH}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \). The coefficient of \( \mathrm{O}_{2} \) in the balanced equation is:
A) 2
B) 6
C) 8
D) 9
3) The molar mass of methanol \( \left(\mathrm{CH}_{3} \mathrm{OH}\right) \) is:
A) \( 45.06 \mathrm{~g} / \mathrm{mol} \)
B) \( 32.06 \mathrm{~g} / \mathrm{mol} \)
C) \( 46 \mathrm{~g} / \mathrm{mol} \)
D) \( 30 \mathrm{~g} / \mathrm{mol} \)
4) Consider the reaction: \( \mathrm{SO}_{2}+2 \mathrm{H}_{2} \mathrm{~S} \rightarrow 3 \mathrm{~S}+2 \mathrm{H}_{2} \mathrm{O} \)
How much sulfur (in grams) is produced from 21.5 grams of \( \mathrm{H}_{2} \mathrm{~S} \) with excess \( \mathrm{SO}_{2} \) ? \( \left(\mathrm{H}_{2} \mathrm{~S}\right. \) molar mass is \( 34.0 \mathrm{~g} / \mathrm{mol} \)
A) 9.70 g
B) 14.4 g
C) 21.5 g
D) 30.3 g
5) Calculate the volume (in mL ) of 10.0 M aqueous solution of \( \mathrm{HF}(\mathrm{aq}) \) required to react completely with 4.72 g of \( \mathrm{Ca}(\mathrm{OH})_{2} \) according to the following reaction? (molar mass of \( \mathrm{Ca}(\mathrm{OH})_{2} \) is \( 74.10 \mathrm{~g} / \mathrm{mol} \) ).
\[
2 \mathrm{HF}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow \mathrm{CaF}_{2}+2 \mathrm{H}_{2} \mathrm{O}
\]
A) 12.8 mL
B) 637 mL
C) 25.5 mL
D) 39.2 mL
6) In the reaction shown below, what species is reduced?
\[
2 \mathrm{NaI}+\mathrm{Br}_{2} \rightarrow 2 \mathrm{NaBr}+\mathrm{I}_{2}
\]
A) \( I^{-} \)
B) \( \mathrm{Na}^{+} \)
C) \( \mathrm{Br}_{2} \)
D) \( \mathrm{Br}^{-} \)
7) All of the following are strong acids except:
A) HBr
B) HF
C) \( \mathrm{HNO}_{3} \)
D) HI
8) In osmosis, water (solvent) flows from \( \qquad \) to \( \qquad \)
A) concentrated solution, pure water
B) low solute concentration; high solute concentration
C) high solute concentration; low solute concentration
D) none of the above
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