chem

Andi performs the calculation that is shown below. mc007-1.jpg How should the answer be reported using the correct number of significant figures? 3.59 3.591 3.6 4

a

The balanced chemical equation for the reaction of copper (Cu) and silver nitrate (AgNO3) is shown below. Cu + 2AgNO3 mc001-1.jpg 2Ag + Cu(NO3)2 How many moles of copper must react to form 3.50 mol of Ag? 0.175 mol 1.75 mol 7.00 mol 17.0 mol

b

What is the correct way to write 1,550,000,000 in scientific notation? 1.55 mc030-1.jpg 109 1.55 mc030-2.jpg 1010 15.5 mc030-3.jpg 108 15.5 mc030-4.jpg 109

a

Which reason best explains why plasmas are good conductors of electricity? They have mobile charged particles. They are at extremely high temperatures. They are made up of particles in fixed positions. They have slow-moving nuclei that carry electricity.

a

Which is an example of a plasma that occurs in nature? a burning tree the radiant sun a melting candle an electric current

b

What is the molar mass of Al2(SO4)3? 150.03 g/mol 278.03 g/mol 342.17 g/mol 450.09 g/mol

c

The molar mass of hydrogen (H2) is 2.02 g/mol. A sample contains 4.00 mol of H2. What is the mass, in grams, of this sample? 1.98 2.02 4.00 8.08

d

Which is the formula mass of (NH4)2SO4? 96.07 amu 114.12 amu 116.17 amu 132.17 amu

d

Which is the molar mass of H2O? 10.02 g/mol 16.00 g/mol 17.01 g/mol 18.02 g/mol

d

Which low-energy state of condensed matter is characterized by structural rigidity and resistance to changes of shape or volume? gas liquid plasma solid

d

b

Scientists use scientific notation to represent very small or very large numbers because this notation increases the accuracy of measured quantities. convenience in using the numbers. number of significant figures. precision of measurements.

A group of students are wandering around a room. When their teacher claps, the students sit down wherever they are. This situation best models the formation of which type of solid? an amorphous solid because the particles do not have a regular structure an amorphous solid because the motion of the particles stopped a crystalline solid because the moving particles lock into fixed positions a crystalline solid because the particles have a long-range order

a

Consider the balanced equation below. mc027-1.jpg What is the mole ratio of mc027-2.jpg to Fe? 1:3 1:4 3:1 4:3

a

Which measurement of length is the smallest? 9 mc016-1.jpg 10-6 m 7 mc016-2.jpg 10-5 m 7 mc016-3.jpg 101 m 9 mc016-4.jpg 102 m

a

A student has a sample of isopropanol (C3H7OH) that has a mass of 78.6 g. The molar mass of isopropanol is 60.1 g/mol. How many moles of isopropanol are contained in this sample? 0.765 1.31 78.6 4,720

b

Consider the reaction below. 2H2 + O2 mc015-1.jpg 2H2O How many moles of water are produced from 13.35 mol of oxygen? 6.675 mol 26.70 mol 53.40 mol 66.75 mol

b

The reaction below shows how silver chloride can be synthesized. AgNO3 + NaCl mc017-1.jpg NaNO3 + AgCl How many moles of silver chloride are produced from 15.0 mol of silver nitrate? 1.0 mol 15.0 mol 30.0 mol 45.0 mol

b

Consider the reaction below. 2Al2O3 mc031-1.jpg 4Al + 3O2 How many moles of oxygen are produced when 26.5 mol of aluminum oxide are decomposed? 17.7 mol 19.9 mol 39.8 mol 53.0 mol

c

What happens when the kinetic energy of molecules increases so much that electrons are released by the atoms, creating a swirling gas of positive ions and negative electrons? Matter changes to a solid state. Matter changes to a liquid state. Matter changes to a plasma state. Matter changes to a gaseous state.

c

A chemist has 2.0 mol of methanol (CH3OH). The molar mass of methanol is 32.0 g/mol. What is the mass, in grams, of the sample? 16 30 32 64

d

The equation below shows hydrogen reacting with oxygen to produce water. 2H2 + O2 mc028-1.jpg 2H2O If 16 mol of oxygen were reacted with excess hydrogen gas, how many moles of water would be produced? 4.0 mol 8.0 mol 16 mol 32 mol

d

The molar mass of nitrogen (N2) is 28.02 g/mol. What is the mass, in grams, of 4.60 mol of N2? 0.164 6.09 23.4 129

d

Which is the correct way to write 602,200,000,000,000,000,000,000 in scientific notation?

d

Acid rain can be destructive to both the natural environment and human-made structures. The equation below shows a reaction that occurs that may lead to the formation of acid rain. 3NO2 + H2O mc025-1.jpg 2HNO3 + NO How many moles (precise to the nearest 0.01 mol) of nitric acid are produced from 300.00 mol of nitrogen dioxide? 200.00 mol 200.09 mol 450.00 mol 450.02 mol

a

Keisha makes a table to compare plasmas and solids. Plasma Solid Kinetic energy X Density Y Which labels belong in the cells marked X and Y? X: High Y: High X: High Y: Low X: Low Y: High X: Low Y: Low

a

The chemical equation below shows the reaction between tin (Sn) and hydrogen fluoride (HF). Sn + 2HF mc017-1.jpg SnF2 + H2 The molar mass of HF is 20.01 g/mol. How many moles of Sn are required to react with 40 g of HF? 1 2 3 4

a

What is the molar mass of a substance? the mass in grams of one mole of a substance the number of particles in one gram of a substance the number of moles in one gram of a substance the mass in grams of one particle of a substance

a

Which number is equal to -906,060? -9.0606 mc020-1.jpg 105 -9.06 mc020-2.jpg 105 9.06 mc020-3.jpg 10-5 9.0606 mc020-4.jpg 10-5

a

Consider the balanced equation below. 8H2 + S8 mc006-1.jpg 8H2S Based on the mole ratios, what can most likely be predicted? 1 mol of hydrogen will react with 1 mol of sulfur. 8 mol of hydrogen will react with 1 mol of sulfur. 8 mol of hydrogen will react with 8 mol of sulfur. 16 mol of hydrogen will react with 8 mol of sulfur.

b

How are a mole and a dozen similar? Each represents a certain mass of material. Each names a given number of objects. Each identifies a specific volume. Each measures a given number of amus.

b

Joseph divides 8.64 by 2.0. How many significant figures should his answer have?

b

The Haber process can be used to produce ammonia (NH3) from hydrogen gas (H2) and nitrogen gas (N2). The balanced equation for this process is shown below. 3H2 + N2 mc025-1.jpg 2NH3 The molar mass of NH3 is 17.03 g/mol. The molar mass of H2 is 2.0158 g/mol. In a particular reaction, 0.575 g of NH3 forms. What is the mass, in grams, of H2 that must have reacted, to the correct number of significant figures? 0.1 0.102 0.10209 0.1021

b

The chemical equation below shows the burning of magnesium (Mg) with oxygen (O2) to form magnesium oxide (MgO). 2Mg + O2 mc019-1.jpg 2MgO Niven wants to calculate the mass of MgO that is produced by the burning of 28.0 g of Mg. What is the first step in Niven's calculation? Balance the chemical equation. Convert grams of Mg to moles. Determine whether heat is given off by this reaction. Find the number of Mg atoms in the sample.

b

Consider the reaction below. 2H2O mc030-1.jpg 2H2 + O2 How many moles of hydrogen are produced when 6.28 mol of oxygen form? 3.14 mol 6.28 mol 12.6 mol 25.2 mol

c

How does the number of molecules in 1 mol of oxygen compare with the number of molecules in 1 mol of nitrogen? 1 mol of oxygen has fewer molecules. 1 mol of oxygen has more molecules. Each sample has the same number of molecules. The molecules cannot be compared without knowing the mass.

c

Temperature depends on the average kinetic energy of the particles in a sample. How does this help with explaining why a plasma-based light does not have a high temperature? No particles in the plasma have high kinetic energy. The fastest particles have the greatest mass. Most particles in the plasma are heavy and slow. The fastest particles transfer most of their energy through collisions.

c

The O-O bond length in oxygen gas is 1.20741 mc026-1.jpg 10-10 m. The atomic radius is exactly mc026-2.jpg of the O-O bond length. Which is the atomic radius of oxygen, correctly written in scientific notation with the correct number of significant figures?

c

The chemical equation below shows the reaction between carbon dioxide (CO2) and lithium hydroxide (LiOH). CO2 + 2LiOH mc011-1.jpg Li2CO3 + H2O The molar mass CO2 is 44.01 g/mol. How many moles of LiOH are needed to react completely with 25.5 g of CO2? 0.290 0.579 1.16 1.73

c

The following balanced equation shows the formation of ethane (C2H6). C2H2 + 2H2 mc022-1.jpg C2H6 How many moles of hydrogen are needed to produce 13.78 mol of ethane? 3.445 mol 6.890 mol 27.56 mol 55.12 mol

c

What is Avogadro's number? the number of atoms in exactly 14.00 g of carbon-12 the number of atoms in a kilogram of any substance the number of atoms, molecules, ions, formula units, or other particles in a mole of a substance the number of atoms, molecules, ions, formula units, or other particles in a gram of a substance

c

What is the molar mass of CHCl3? 48.47 g/mol 83.92 g/mol 119.37 g/mol 121.39 g/mol

c

Which is an example of plasmas in nature? solar cells plasma balls auroras clouds

c

Which is the correct way to represent 0.0035 kg by using scientific notation? -3.5 mc018-1.jpg 103 kg -3.5 mc018-2.jpg 10-3 kg 3.5 mc018-3.jpg 10-3 kg 3.5 mc018-4.jpg 103 kg

c

Which of these rules is applicable to subtracting two values that have different numbers of decimal places (for example, subtracting 2.1 from 2.15)? The answer is less accurate than either value. The answer is more precise than either value. The answer has the same number of decimal places as the least precise value. The answer has the same number of significant figures as the most precise value.

c

A plasma that has particles that never collide frequently enough to exchange kinetic energy and never reach a temperature equal to the surroundings is categorized as a thermal plasma. ionized plasma. low density plasma. nonthermal plasma.

d

Lakshmi has a sample of ammonium nitrate (NH4NO3) that has a mass of 40.10 g. She knows that the molar mass of NH4NO3 is 80.0432 g/mol. To the correct number of significant digits, how many moles of NH4NO3 does the sample contain? 0.50 0.500979 0.500980 0.5010

d

Passing an electric current through a sample of water (H2O) can cause the water to decompose into hydrogen gas (H2) and oxygen gas (O2) according to the following equation. 2H2O mc026-1.jpg 2H2 + O2 The molar mass of H2O is 18.01 g/mol. The molar mass of O2 is 32.00 g/mol. What mass of H2O, in grams, must react to produce 50.00 g of O2? 14.07 23.05 28.14 56.28

d

Which best compares 1 mol of sodium chloride to 1 mol of aluminum chloride? Both have the same molar mass. Both have the same number of ions. Both are made up of 6.02 mc014-1.jpg 1023 molecules. Both are made up of 6.02 mc014-2.jpg 1023 formula units.

d

Which description best characterizes the motion of particles in a solid? slow but able to move past one another fast and widely spaced not moving vibrating around fixed positions

d

Which statement best describes a mole? It is 12 units of a given substance. It contains 6.02 mc001-1.jpg 1023 grams of sodium chloride. It is the mass of 12 carbon atoms. It contains 6.02 mc001-2.jpg 1023 particles of a given substance.

d

Which is the correct way to write 602,200,000,000,000,000,000,000 in scientific notation? 6022 mc017-1.jpg 1019 6022 mc017-2.jpg 1020 6.022 mc017-3.jpg 1022 6.022 mc017-4.jpg 1023

dd