Q: How many water molecules are present in 2.50 mol of $$H_2O$$? (Avogadro's number $$= 6.022 \times 10$$^{23}$$ molecules/mol)

$$1.51 \times 10$$^{24}$$ molecules

Question 1

How many water molecules are present in 2.50 mol of $$H_2O$$? (Avogadro's number $$= 6.022 	imes 10$$^{23}$$ molecules/mol)

Accepted Answer

$$1.51 	imes 10$$^{24}$$ molecules

Question 2

Which molecule has the largest molar mass?

Accepted Answer

$$H_3PO_4$$

Question 3

A patient is prescribed 40 mg of Solu-Medrol per dose. If the available solution contains 12.5 mg/2 mL, how many mL should the nurse administer per dose?

Accepted Answer

6.4 mL/dose

Question 4

How many moles of uric acid are in 281.7 g of uric acid? (Molar mass = 168.11 g/mol)

Accepted Answer

1.68 mol

Question 5

Given the reaction $$3NO_2(g) + H_2O(g) \rightarrow 2HNO_3(g) + NO(g)$$, how many moles of $$H_2O$$ are required to react completely with 6 moles of $$NO_2$$?

Accepted Answer

2 moles

Question 6

How many grams of $$H_2O$$ are required to react completely with 3.0 moles of $$NO_2 in $$the reaction $$3NO_2(g) + H_2O(g) \rightarrow 2HNO_3(g) + NO(g)$$? ($$M_{H_2O} = 18.02 g/$$mol)

Accepted Answer

18 g

Question 7

How many moles of NaCl are in 3.75 L of a 0.485 M solution?

Accepted Answer

1.82 mol

Question 8

Which compound acts as a base when dissolved in water?

Accepted Answer

$$Ca(OH)_2$$

Question 9

A sample of lake water has a pH of 6.3. Which description best characterizes this sample?

Accepted Answer

slightly acidic

Question 10

Which reaction is NOT an acid-base neutralization?

Accepted Answer

$$BaCl_2(aq) + Na_2SO_4(aq$$) \rightarrow $$BaSO_4(s) + 2$$NaCl(aq)$$

Question 11

How many moles of $$HCl$$ are required to completely neutralize 1.85 moles of $$Mg(OH)_2$$? ($$2HCl(aq) + Mg(OH)_2(aq) \rightarrow 2H_2O(l) + $$MgCl_2$$(aq))$$

Accepted Answer

3.70 mol

Question 12

If 16.2 mL of a 0.125 M $$HNO_3$$ solution is required to completely neutralize 10.5 mL of a NaOH solution, what is the concentration of the NaOH?

Accepted Answer

0.193 M

Question 13

Which chemical equation correctly represents the synthesis of methanol ($$CH_3OH) $$based on the equilibrium expression $$K = \frac{[CH_3OH]}{[CO][H_2$]^2}$$?

Accepted Answer

$$CO(g) + 2H_2(g) \rightleftharpoons CH_3OH(g)$$

Question 14

Two sealed containers (1.25 L each at 95°C) contain 2.75 g of He and 2.75 g of Ar, respectively. Which statement is correct?

Accepted Answer

The flask containing helium has a higher pressure than the flask containing argon.

Question 15

Select the most polar covalent bond.

Accepted Answer

$$C-O$$

Question 16

Refer to the Lewis structures shown. Classify $$PBr_3$$ and $$CH_2O as $$polar or nonpolar.

Accepted Answer

$$PBr_3 is $$polar, $$CH_2O is $$polar

Question 17

Which is the most important type of intermolecular force between the side chain of serine and water?

Accepted Answer

hydrogen bonds

Question 18

Name the molecular compound $$BF_3.$$

Accepted Answer

boron trifluoride

Question 19

Gold-198 has a half-life of 2.7 days. How many days is three half-lives?

Accepted Answer

8.1 d

Question 20

Which pair of atoms is most likely to form a covalent bond?

Accepted Answer

C and O

Final Exam Study Guidance: Molecules, Polarity, and Intermolecular Forces

Guida di studio - Domande di pratica

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