Q: A 15.0 g sample of aluminum ($$c = 0.220 \ \mathrm{cal/g^\circ C}) is $$heated from $$15.0^\circ \mathrm{C} to$$ $$55.0^\circ \mathrm{C}. $$How much heat is required?

$$Q = 0.220 \times 15.0 \times (55.0 - 15.0) = 132 \ \mathrm{cal}$$

Q: A liquid sample of 2.70 kg at $$20.1^\circ \mathrm{C}$$ absorbs 134 kcal of heat. If the specific heat capacity is $$1.50 \ \mathrm{kcal/kg^\circ C}$$, what is the final temperature?

$$T_f = 20.1^\circ \mathrm{C} + \frac{134}{2.70 \times 1.50} = 53.0^\circ \mathrm{C}$$

Question 1

Which of the following best describes the difference between ionic and covalent compounds?

Accepted Answer

Ionic compounds are formed by the transfer of electrons from metals to nonmetals, while covalent compounds are formed by the sharing of electrons between nonmetals.

Question 2

Which of the following compounds is most likely to be ionic?

Accepted Answer

NaCl

Question 3

Given the following reaction: $$2C_2H_6(g) + 7O_2(g) \rightarrow 4CO_2(g) + 6H_2O(g)$$, what type of reaction is this?

Accepted Answer

Combustion

Question 4

Which of the following molecules is polar?

Accepted Answer

CH\_3F

Question 5

A 15.0 g sample of aluminum ($$c = 0.220 \ \mathrm{cal/g^\circ C}) is $$heated from $$15.0^\circ \mathrm{C} to$$ $$55.0^\circ \mathrm{C}. $$How much heat is required?

Accepted Answer

$$Q = 0.220 	imes 15.0 	imes (55.0 - 15.0) = 132 \ \mathrm{cal}$$

Question 6

Which of the following best explains why water has a higher boiling point than methane ($$CH_4$$)?

Accepted Answer

Water molecules form hydrogen bonds, which are stronger than the London dispersion forces in methane.

Question 7

Which of the following is the correct formula for chromium(III) carbonate?

Accepted Answer

Cr\_2(CO\_3)\_3

Question 8

Which of the following statements about London dispersion forces is correct?

Accepted Answer

They are present in all molecules, but are the only forces in nonpolar molecules.

Question 9

Balance the following chemical equation: $$(NH_4$)_2Cr_2O_7 \rightarrow Cr_2O_3 + H_2O + N_2$

Accepted Answer

$$(NH_4$)_2Cr_2O_7 \rightarrow Cr_2O_3 + 4H_2O + N_2$

Question 10

Which of the following best describes the energy change when a chemical reaction absorbs heat from the surroundings?

Accepted Answer

The reaction is endothermic and $$\Delta H is $$positive.

Question 11

Which of the following is a correct statement about the formation of ions?

Accepted Answer

Metals tend to lose electrons to form cations.

Question 12

A liquid sample of 2.70 kg at $$20.1^\circ \mathrm{C}$$ absorbs 134 kcal of heat. If the specific heat capacity is $$1.50 \ \mathrm{kcal/kg^\circ C}$$, what is the final temperature?

Accepted Answer

$$T_f = 20.1^\circ \mathrm{C} + \frac{134}{2.70 	imes 1.50} = 53.0^\circ \mathrm{C}$$

Question 13

Which of the following is the correct formula for sodium bisulfite?

Accepted Answer

NaHSO\_3

Question 14

Which of the following best describes a double displacement reaction?

Accepted Answer

Two compounds exchange ions to form two new compounds.

Question 15

Which of the following molecules is nonpolar?

Accepted Answer

CCl\_4

Question 16

Which of the following is the correct balanced equation for the reaction: $$C_2H_4(g) + O_2$(g) \rightarrow H_2O(g) + CO_2$(g)$$?

Accepted Answer

$$C_2H_4 + 3O_2 \rightarrow 2H_2O + 2CO_2$$

Question 17

Which of the following is NOT a type of intermolecular force?

Accepted Answer

Ionic bond

Question 18

Which of the following best describes the relationship between boiling point and intermolecular forces?

Accepted Answer

The stronger the intermolecular forces, the higher the boiling point.

Question 19

Which of the following is the correct formula for calcium acetate?

Accepted Answer

Ca(C\_2H\_3O\_2)\_2

Question 20

Which of the following best describes the process of balancing a chemical equation?

Accepted Answer

Adding coefficients in front of compounds to ensure the same number of atoms of each element on both sides.

Introduction to Chemistry: Chemical Bonds, Energy, and Chemical Reactions Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard