Q: A sphere of persimmon wood has a diameter of 8.32 cm and a mass of 234 g. Calculate the density of the sphere using $$\text{Density} = \frac{\text{mass}}{\text{volume}}$$ and determine if it will float in water ($$\text{density of water} = 1.00\ \text{g/mL}).$$

The density of the sphere is $$0.776\ \text{g/mL}. $$The sphere will float in water.

Q: Methane ($$\text{CH}_4) $$and ethylene ($$\text{C}_2\text{H}_2) $$are composed of carbon and hydrogen. Using the law of multiple proportions, how much hydrogen would react with 1.78 g of carbon to produce methane and to produce ethylene?

for $$\text{CH}_4$$: $$0.299\ \text{g H}$$; for $$\text{C}_2\text{H}_2$$: $$0.149\ \text{g H}$$

Q: Given the following data, which ions are present in the solution? 1. Addition of sodium chloride results in a precipitate. 2. Addition of potassium sulfate does not result in a precipitate. 3. Addition of sodium carbonate results in a precipitate.

$$\text{Ag}^+$$ and $$\text{Sr}^{2+}$$

Q: Identify the elements in their standard states required for the formation equation of $$\text{C}_6\text{H}_{12}\text{O}_6(s) $$and write the balanced reaction. Find the standard enthalpy of formation using the standard table of values.

$$3\ \text{C}(s) + 6\ \text{H}_2(g) + 3\ \text{O}_2(g) \rightarrow \text{C}_6\text{H}_{12}\text{O}_6(s);\ \Delta H_f = -2645.03\ \text{kJ/mol}$$

Question 1

A sphere of persimmon wood has a diameter of 8.32 cm and a mass of 234 g. Calculate the density of the sphere using $$	ext{Density} = \frac{	ext{mass}}{	ext{volume}}$$ and determine if it will float in water ($$	ext{density of water} = 1.00\ 	ext{g/mL}).$$

Accepted Answer

The density of the sphere is $$0.776\ 	ext{g/mL}. $$The sphere will float in water.

Question 2

A block of solid that weighs 58.16 g is placed in a container with a 100 mL capacity. It is then filled to capacity with benzene (density $$= 0.864\ 	ext{g/mL}) $$and the combined weight is 96.15 g. What is the density of the solid?

Accepted Answer

4.18 g/mL

Question 3

Octane is a combustible liquid. Is combustibility a physical or chemical property?

Accepted Answer

Chemical property

Question 4

Methane ($$	ext{CH}_4) $$and ethylene ($$	ext{C}_2	ext{H}_2) $$are composed of carbon and hydrogen. Using the law of multiple proportions, how much hydrogen would react with 1.78 g of carbon to produce methane and to produce ethylene?

Accepted Answer

for $$	ext{CH}_4$$: $$0.299\ 	ext{g H}$$; for $$	ext{C}_2	ext{H}_2$$: $$0.149\ 	ext{g H}$$

Question 5

Why do chemists classify elements as transition metals or representative elements?

Accepted Answer

To predict chemical reactions and bonding behavior based on element classification.

Question 6

A sample of nicotine, $$	ext{C}_{10}	ext{H}_{14}	ext{N}_2$$, contains $$3.561 	imes 10$$^{25}$$ nitrogen atoms. Calculate the number of nicotine molecules in the sample.

Accepted Answer

15.42 mol

Question 7

Suppose the extraction of Fe from hematite ($$	ext{Fe}_2	ext{O}_3) is $$carried out with 85.6% yield for the first two reactions and 95.6% yield for the third. If you start with 5.00 g of hematite, what mass of iron can be obtained?

Accepted Answer

2.46 kg Fe

Question 8

What is the correct name for the ion $$	ext{AsO}_4$$^{3-}$$?

Accepted Answer

arsenate ion

Question 9

Which compound will travel further on a TLC plate if the mobile phase is highly polar?

Accepted Answer

A compound with low affinity for the stationary phase and high affinity for the mobile phase.

Question 10

Convert $$5.6 	imes 10^3$ to match the exponent of 2.1$$ 	imes $$10^5$$ for addition.

Accepted Answer

$$0.056 	imes 10^5$

Question 11

Which experiment can be used to determine whether a mixture is a solution or a colloid?

Accepted Answer

All of the above

Question 12

Which statement is true for the reaction $$	ext{CH}_4 (g) + 2\ 	ext{O}_2 (g) ightarrow 	ext{CO}_2 (g) + 2\ 	ext{H}_2	ext{O} (l)$$?

Accepted Answer

The reaction is a redox reaction where the oxygen is reduced and the carbon is oxidized.

Question 13

Given the following data, which ions are present in the solution? 1. Addition of sodium chloride results in a precipitate. 2. Addition of potassium sulfate does not result in a precipitate. 3. Addition of sodium carbonate results in a precipitate.

Accepted Answer

$$	ext{Ag}^+$$ and $$	ext{Sr}^{2+}$$

Question 14

Suppose the electrical conductivity of a solution is directly proportional to the total ions dissolved. Using titration, which graph matches the addition of $$0.150\ 	ext{M}\ 	ext{NaOH} to$$ $$1.00\ 	ext{L} of$$ $$0.150\ 	ext{M}\ 	ext{HCN}$$ solution?

Accepted Answer

C: (I) B: (II) A: (III)

Question 15

0.672 g of $$	ext{SO}_2$$ and 1.28 g of Ar at 289 K are both present in a 25.00-L flask. What is the partial pressure of Ar in mmHg?

Accepted Answer

3.04 mmHg

Question 16

If the temperature (in Kelvin) of a gas in a cylinder is doubled while keeping the volume constant, how will the pressure change?

Accepted Answer

The pressure will be doubled.

Question 17

Which of the following statements is true for the Maxwell-Boltzmann distribution if gases A and B are different gases?

Accepted Answer

The average speed is highest for gas A only.

Question 18

A gas sample in a cylinder is heated from 200 K to 400 K while the pressure is decreased from 2.6 atm to 1.3 atm. Which image best represents the final state of the gas?

Accepted Answer

Image c

Question 19

The complete combustion of a hydrocarbon produced 17.2 g of $$	ext{CO}_2$$ and 2.45 g of $$	ext{H}_2	ext{O}. $$The heat given off was 463 kJ. What is the mass of the substance combusted?

Accepted Answer

4.97 g

Question 20

Identify the elements in their standard states required for the formation equation of $$	ext{C}_6	ext{H}_{12}	ext{O}_6(s) $$and write the balanced reaction. Find the standard enthalpy of formation using the standard table of values.

Accepted Answer

$$3\ 	ext{C}(s) + 6\ 	ext{H}_2(g) + 3\ 	ext{O}_2(g) ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6(s);\ \Delta H_f = -2645.03\ 	ext{kJ/mol}$$

General Chemistry Study Guidance: Unit 1 Exam – Set 2

Guida di studio - Domande di pratica

Study guide - Flashcard