CHM151 Rio Salado Midterm

Indicate what type(s) of reaction each of the following represents: 1.H2O(g) + C(s)⟶CO(g) + H(g) 2.2KClO3(s)⟶2KCl(s) + 3O2(g) 3.Al(OH)3(aq) + 3HCl(aq)⟶AlCl3(aq) + 3H2O(l) 4.Pb(NO3)2(aq) + H2SO4(aq)⟶PbSO4(s) + 2HNO3(aq)

(1) oxidation-reduction, (2) oxidation-reduction, (3) acid-base, (4) precipitation

Determine the enthalpy change under standard state conditions for 2Al(s) + Fe2O3(s)⟶Al2O3(s) + 2Fe(s). (Use Appendix G in text.)

-852 kJ

Convert 450 mg to kg.

0.00045 kg

Determine the molarity of 0.515 g of H2SO4 in 1.00 L of solution.

0.00525 M

Determine the molarity of 0.000889 g of glycine, C2H5NO2 in 1.05 mL of solution.

0.0113 M

Determine the molarity of 20.54 g of Al(NO3)3 in 1575 mL of solution.

0.0612 M

What is the answer to the following equation with proper significant figures? 12.1 - 3.25/125

0.071

Convert 250 mL to L

0.25L

What is the molarity of HCl if 35.23 mL of a solution of HCl contain 0.3366 g of HCl?

0.2630 M

A 70.0 g piece of metal at 80.0 °C is placed in 100 g of water at 22.0 °C contained in a calorimeter like that shown in Figure 3 Section 5.2 of your textbook. The metal and water come to the same temperature at 24.6 °C. What is the specific heat of the metal?

0.28 J/g°C

Consider the titration of 15.00 mL of NaCl of unknown concentration with 20.22 mL of 0.2503 M AgNO3 to reach an endpoint. What is the concentration of the NaCl solution? AgNO3(aq) + NaCl(aq)⟶AgCl(s) + NaNO3(aq)

0.3374 M

How much heat, in calories, must be added to a 75.0 g iron block with a specific heat of 0.449 J/g °C to increase its temperature from 25 °C to its melting temperature of 1535 °C?

1.21 x 10^4 cal

Determine the number of moles of 0.1488 g of phosphoric acid, H3PO4.

1.518 x 10-3 mol

Calculate the mass of the solute 75.0 mL of 2.2 x 10-5 M H2SO4.

1.6 x 10^-4 g

What is the total mass of hydrogen in C12H10O6?

10.08 amu

Calculate the heat capacity, in joules per degree C, of 28.4g of water.

119 J/°C

A pint of premium ice cream can contain 1100 Calories. What mass of fat, in grams, must be produced in the body to store an extra 1.1 x 103 Calories if the average number of calories for fat is 9.1 Calories/g?

120 g

When 1.0 g of fructose, C6H12O6 (s), a sugar commonly found in fruits, is burned in oxygen in a bomb calorimeter, the temperature of the calorimeter increases by 1.58 °C. If the heat capacity of the calorimeter and its contents is 9.90 kJ/°C, what is q for this combustion?

15.6 kJ

How many cm are in 15 m?

1500 cm

What is the mass of chlorine gas necessary to react with 12.0g of sodium metal, Na, to produce NaCl?

18.5 g

What mass of HCl is contained in 45.0 mL of an aqueous HCl solution that has a density of 1.19 g cm-3 and contains 37.21% HCl by mass?

19.9 g

What volume of 0.200 M hydrochloric acid solution can be prepared from the HCl produced by the reaction of 25.0g of NaCl with excess sulfuric acid? NaCl(s) + H2SO4(l)⟶HCl(g) + NaHSO4(s)

2.14 L

What is the number of moles and the mass of Mg required to react with 7.50g of HCl and produce MgCl2 and H2?

2.50 g

Determine the enthalpy change under standard state conditions for SnO(s) + CO(g)⟶Sn(s) + CO2 (g). (Use Appendix G in text.)

2.8 kJ

How much heat is produced by combustion of 125 g of methanol under standard state conditions? (Use the Standard Molar Enthalpies of Combustion table in Section 5.3 in your textbook)

2.83 x 10^3 kJ

If the density of mercury is 13.6 g/cm3, how much mass would be needed to fill a 3 L vessel?

221 g

If room temperature is usually defined as 25°, what is room temperature in Kelvin (k)?

298 K

Solid potassium chlorate, KClO3, decomposes to form solid potassium chloride and diatomic oxygen gas. What is the balanced equation describing this reaction from the following?

2KClO3 → 2KCl(s) + 3O2(g)

The level of mercury in a stream was suspected to be above the minimum considered safe (1 part per billion by weight). An analysis indicated that the concentration was 0.68 parts per billion. Assume a density of 1.0 g/mL and calculate the molarity of mercury in the stream.

3.4 x 10^-9 M

What is the mass of solute in 200.0 L of a 1.556 M solution of KBr?

3.703 x 10^4 g

What volume of 0.08892 M HNO3 is required to react completely with 0.2352g of potassium hydrogen phosphate? 2HNO3(aq) + K2HPO4(aq)⟶H2PO4(aq) + 2KNO3(aq)

30.37 mL

Balance the following reaction: Fe(s) + H2O(l)⟶Fe3O4(s) + H2(g)

3Fe(s) + 4H2O(l)⟶Fe3O4(s) + 4H2(g)

How many kilojoules of heat will be released when exactly 1 mole of iron, Fe, is burned to form Fe2O3 (s) at standard state conditions? (Use Appendix G in text.)

412 kJ

How much would the temperature of 200.0 g of water increase if 36.5 kJ of heat were added?

43.6°C

In a laboratory experiment, the reaction of 3.0 mol of H2 with 2.0 mol of I2 produced 2.0 mol of HI. Determine the percent yield for this reaction

50%

Balance each of the following equations according to the half-reaction method: H2O2(aq) + MnO4−(aq)⟶Mn2+(aq) + O2(g) (in acid)

5H2O2(aq) + 2MnO4−(aq) + 6H3O+(aq) ⟶ 2Mn2+(aq) + 5O2(g) + 14H2O(l)

How many cm are in 24 inches?

60.96 cm

Calculate the molar mass of nitric acid, HNO3.

63.013 g/mol

If the density of iron is 7.9 g/cm3, how much volume would 5.00 kg of iron occupy?

633 mL

I2 is produced by the reaction of 0.5235 mol of CuCl2 according to the following equation: 2CuCl2 + 4KI⟶2CuI + 4KCl + I2. What is the mass of the I2 produced?

66.43 g

When 50.0 g of 0.200 M NaCl(aq) at 24.1 °C is added to 100.0 g of 0.100 M AgNO3 (aq) at 24.1 °C in a calorimeter, the temperature increases to 25.2 °C as AgCl(s) forms. Assuming the specific heat of the solution and products is 4.20 J/g °C, calculate the approximate amount of heat in joules produced.

693 J

How many neutrons are in carbon-13?

7

An aluminum kettle weighs 1.05 kg. How much heat in joules is required to increase the temperature of this kettle from 23.0 °C to 99.0 °C?

7.2 x 10^4 J

A hypothetical element has three isotopes with the mass of 8, 9, and 11 amu. The natural abundance of the isotopes for this element is 80%, 15%, and 5%, respectively. What is the molecular weight of the element?

8.30 amu

What the symbol for the ion with 36 electrons, 35 protons, and 45 neutrons?

80Br-1

Determine the percent of SO42- in Al2(SO4)3.

81.71%

A 45g aluminum spoon (specific heat 0.88 J/g°C) at 24 °C is placed in 180 mL (180g) of coffee at 85 °C and the temperature of the two become equal. What is the final temperature when the two become equal? Assume that coffee has the same specific heat as water.

82°C

A sample of 0.53g of carbon dioxide was obtained by heating 1.31g of calcium carbonate. What is the percent yield for this reaction? CaCO3(s)⟶CaO(s) + CO2(s)

92%

Which of the following symbols is the symbol for gold?

Ag

Which postulate of Dalton's theory is consistent with the following observation concerning the weights of reactants and products? When 100 grams of solid calcium carbonate is heated, 44 grams of carbon dioxide and 56 grams of calcium oxide are produced.

Atoms are neither created nor destroyed during a chemical change.

Complete and balance the following oxidation-reduction reaction: Ba(s) + HBr(aq) →

Ba(s) + 2HBr(aq) → BaBr2(aq) + H2(g)

Which of the following is an example of a chemical change?

Burning of magnesium

Which element has the symbol Cs?

Cesium

A 2.0-liter volume of hydrogen gas combined with 1.0 liter of oxygen gas to produce 2.0 liters of water vapor. Does oxygen undergo a chemical or physical change?

Chemical Change

Due to periodicity, which of the following elements has chemical behavior similar to that of fluorine?

Chlorine

10.0 g of water that can occupy a 10.0 cm3 of volume is an example of an intrinsic or extensive property?

Extensive property

Which contains the greatest number of moles of oxygen atoms: 1 mol of ethanol (C2H5OH), 1 mol of formic acid (HCO2H), or 1 mol of water (H2O)?

Formic acid

How many significant figures does 2.015 have?

Four

How many significant figures should the answer of the following problem have? (5500.1/6776) x 63690.1 =

Four

Determine the oxidation states of the elements in the following compounds: GdCl3 and Mg2Si.

Gd +3, Cl -1, Mg +2, Si -4

Which of the following is considered a state function?

Ice

10.0 g of water freezing at 0 °C is an example of an intrinsic or extensive property?

Intrinsic property

Which of the following statements is NOT true?

Ionic bonds form between two nonmetal elements.

Which is the SI unit for volume?

L

Is the statement "Falling barometric pressure preceded the onset of bad weather." a hypothesis, theory, or a law?

Law

The mass of a lead pipe is 14 lb. Is this observation in the microscopic domain, macroscopic domain, or symbolistic domain?

Macroscopic domain

Chemistry is the study of?

Matter

According to one theory, the pressure of a gas increases as its volume decreases because the molecules in the gas have to move a shorter distance to hit the walls of the container. Does this theory follow a macroscopic or microscopic description of chemical behavior?

Microscopic

The mass of a certain chlorine atom is 35 amu. Is this observation in the microscopic domain, macroscopic domain, or symbolic domain?

Microscopic domain

Determine the empirical formula for compound with the following percent composition: 43.6% phosphorus and 56.4% oxygen.

P2O5

Which statement about subatomic particles is NOT true?

Protons and neutrons have the same charge.

A bottle with a label that reads Al contains aluminum metal. Is this observation in the microscopic domain, macroscopic domain, or symbolic domain?

Symbolic domain

Which of the following is a pure substance?

Table salt, water, baking soda

An experiment requires you to make several measurements. Based on the values in the table below, what would be the best statement that represents the data set if the true value is 0.2135? A B C 0.2139 0.2893 0.2135 0.2130 0.3210 0.2134 0.2133 0.2999 0.3712 0.2135 0.2998 0.3715

The measurements in Trial A are accurate and precise, Trials B and C are neither accurate nor precise.

How many significant figures should be in the answer of the following problem? 2.105 + 3.14 =

Three

Balance the following reaction: TiCl4(s) + H2O(g)⟶TiO2(s) + HCl(g)

TiCl4(s) + 2H2O(g)⟶TiO2(s) + 4HCl(g)

What is the correct formula for zinc(II) sulfate?

Zn(SO4)

Bromine is grouped into the _____.

halides

Is the statement "My truck's gas mileage has dropped significantly, probably because it's due for a tune-up." a hypothesis, theory, or a law?

hypothesis

To calculate the number of neutrons in an atom, you would subtract

mass number from atomic number.

Chlorine is classified as a ______.

nonmetal

Which of the following is a heterogeneous mixture?

oil and vinegar, salad dressing

Isotopes of a given element have the same number of _______ but a different number of ________.

protons, neutrons

Precision is defined as how _____ the measured values are to one another.

reproducible

Is the statement "All life on Earth has evolved from a common, primitive organism through the process of natural selection." a hypothesis, theory, or a law?

theory

Accuracy is defined as how close a measured value comes to a _____.

true value