Chemistry sem 2 final

Air is about 78% nitrogen, 21% oxygen, and 1% other gases. After all the oxygen is removed from a sample of air in a glass tube and the temperature remains, Constant the pressure exerted by the remaining air

reduced by 21%

The coefficients in a chemical equation represent the

relative numbers of moles of reactants and products

Sublimation involves changing from a

solid to A GAS

The average speed of a gas molecule is most directly related to the

temperature of the gas

Classify which of the following is intramolecular

the O-H covalent bond in a water molecule

If a gas and a liquid are at the same temperature and pressure, diffusion occurs much faster in gas because

the particles move faster in a gas and there is a greater distance between them

Fewer steps are required to solve stoichiometry problems when

the reactant is given in moles and the product is sought in moles

If the temperature of gas remains constant, then the pressure of the gas will increase if the

the size of the container decreases

Surface tension is

the tendency of the surface of the liquids to decrease the area

What is correct formula for ammenium phosphate?

(NA4)3 PO4

The pressure of a sample of helium in a 2 mL container is 2atm. If the helium is compressed to a volume of 10mL without changing the temperature. What would be the pressure of the gas?

.4 atm

A sample of helium gas has a volume of 150 mL when it's pressure is 0.955 atm. If the temperature remains constant, what will the pressure of gas be when it has a volume of 175 mL

.82 atm

Determine the number of moles present in 2 grams of calcium phosphate?

0.006 mol

Consider a sample of 10 g of the gaseous hydrocarbon C3H4. How many moles are present in this sample?

0.2 Mole

Compound A has a molar mass of 20 g/mol and compound B has a molar mass of 30 g/mol. What is the mass of 1 mol of Compound A?

1 g

For the reaction: Cl2 + 2KBr --> 2KCl + Br2, how many moles of potassium chloride are produced from 119g of potassium bromide when Cl2 is in excess?

1 mol KCL

Determine the numbers of atoms present in 2 moles of aluminum chromate?

1 x 10^24

How many atoms are present in Ca(HCO3)2

11

What is the molar mass of pure tin?

118.69 g/mol

The pressure of 75L sample of gas is 600mmHg at 20*C. If the temperature drops to 150*V and the column explands to 95mL, what will the pressure of the gas be? - 465.60 mmHg 17. The volume of a gas is 120L at 0.700 atm and 15*C. What volume will it occupy at 0.525 atm and 15*C

160 L

For the reaction: Cl2 + 2KBr --> 2KCl + Br2, how many grams of potassium chloride can be produced from 300g each of Cl2 and KBr?

187.94 g KCl

If cyclohexanol is burned as a fuel according to the following equation, how many moles of oxygen are needed to produce 13.7 mol of carbon dioxide?

19.4 mol O2

A 5.5L sample of argon gas at 420K exerts a pressure of 550kPa. If the gas is compressed to 1.25L and the temperature is lowered to 350K, what its new pressure be?

2,016.67kPa

Ozone,O3, is produced in automobile exhaust by the reaction represented by the equation: NO2 + O2 --> NO + O3 What mass of ozone is predicted to form from the reaction of 2.0 g and NO2 in a car's exhaust and excess oxygen?

2.1g O3

Consider a sample of 10 g of the gaseous hydrocarbon C3H4. How many molecules are present in this sample?

2x10^23 molecules

What is the molar mass of tetraethyl lead, Pb(C2H5)4?

323.48 g/mol

The explosive TNT has the molecular formula C7H5(NO2)3. How many elements make up this compound?

4

For the reaction: 2KClO3 --> 2KCl + 3O2, how many grams of potassium chlorate are required to produce 160.0g of oxygen?

409 g KClO3

The volume of gas at 8*C is 47mL. If the volume increases to 74mal and the pressure is constant, what will the temperature of a gas be?

442.43K

In the equation: 2Al2O3 --> 4Al + 3O2, what is the mole ratio of aluminum to oxygen?

4;3

9.75 atm=

570 mmHg

For the reaction: 2Fe +O2 --> 2FeO, how many grams of iron oxide will be produced from 8.00 mol of iron when O2 is in excess?

574.8g FeO

You collect 550 mL of argon gas at 26C*. What volume will the gas occupy at 46*C if the pressure remains constants?

586.79 mL

How many mole ratios can be correctly obtained from this chemical equation: 2Al2O3 --> 4A + 3O2

6

What is the correct rank (in increasing order) of the following pressure?

76 torr -> 100 mm Hg -> 50 kPa -> 2 atm

For the reaction: N2 + 3H2 --> 2NH3, how many moles of nitrogen are required to produce 18 moles of ammonia?

9

What is the molar mass of copper (II) chloride?

99 g/mol

In the reaction: A + B --> C + D, if there is a more reactant B than is required to completely react with all of A, then

A is the limiting reactant

Match this symbol with the description: an arrow pointing down

A precipitate forms

Match the equation with a double displacement reaction.

AX + BY --> AY + BX

Match the equation type with a decomposition reaction.

AX --> A + X

What is the correct formula for carbon tetrabromide?

CBr4

Liquids and solids are much denser than gases because the particles of liquids amd solids have a

CLOSER ARRANGEMENT

Which of these gases affects the slowest under the same conditions?

CO2

The first part of the name of a binary ionic compound is the

Cation

Changing a subscript in a correctly written chemical formula will

Change the formula so that it no longer represent the same compound

The law that relates the temperature and volume of a gas to each other is known as

Charles law

A mixture of propane and oxygen reacts to form carbon dioxide and water. what type of chemical reaction is this?

Combustion

What is the correct formula copper (I) cyanide?

CuCN

When there is a small decrease in temperature, the average kinetic energy of the particles of liquids

DECREASE

Calcium carbonate, CaCO3, reacts to form calcium oxide, CaO and carbon dioxide, CO2. What type of reaction is this?

Decomposition

What is the correct formula and charge for an Iron (III) ion:

Fe3+

What is the correct name for Fe (NO2)2?

Iron (II) Nitrate

The use of a double arrow in a chemical equation indicates that the reaction

Is reversible

What is the correct notation for a potassium ion whose outer shell is a full octet?

K1+

Which equation below violates the law of conservation of mass?

KCl + Br --> KBr + Cl2

What is the correct notation for a magnesium ion whose outer shell is a full octet?

Mg2+

What is the correct formula for the compound made of magnesium and nitrogen ions?

Mg3N2

Which of the following statements about liquids and gases is not true?

Molecules in a liquid can vibrate and rotate but they are bound in fixed positions

What is the formula name for the compound dinitrogen pentoxide?

N2O5

What is the formula name for the NO-3 ion?

Nitrate

According to the equation for Kinetic energy of a moving object, which gas would have the lowest average velocity?

O3

Which of the following is the regarding single- displacement reactions?

One element replaces another in a compound

What is the correct formula for tetraphosphorus decoxide?

P4O10

What is the correct name for KCl?

Potassium Chloride

Match the symbol with it description: (aq)

Precipitate forms

In the formation of silicon carbide represented by the chemical equation SiO2 + 3C --> SiC + 2CO, 8 mol of each reactant are available for the reaction. What substance is the excess reactant?

SiO2

In the reaction described by the word equation:Sodium + Water --> sodium hydroxide + hydrogen gas

Sodium hydroxide is a product AND water is a reaction

Identify the correctly written word equation for this reaction: 2NaI + Cl2 --> 2NaCl + I2

Sodium iodide reacts with chlorine gas to yield sodium chloride and iodine solid

What follows an element symbol in a chemical formula to indicate the number of atoms of that element in one molecule of the compound:

Subscripted number

In which type of reaction do two or more compounds react to form one product?

Synthesis

What type of chemical reaction is represented by the following word equation:iron + oxygen--> iron(ll) oxide

Synthesis

Which of the following indicates that a chemical equation is balanced?

The number of atoms of each element are the same on both sides of the equation

In a chemical equation the symbol with an arrow with a triangle above the arrow indicates

The reaction must be heated

Which of the following is true regarding double-displacement reactions?

Two Products are formed, the ions of the two reactants must be exchanged, a precipitate may form.

Identify the correctly written word equation for this reaction: 2ZnS + 3O2 --> 2NS + 2SO2

Zinc sulfide reacts with chlorine gas to yield zinc sulfide and sulfide dioxide gas

Suppose that two unlike gases are injected into opposite ends of a long tube at the same time and allowed to diffuse toward the center. they should begin to mix

between the end where the heavier gas entered and the middle

To determine the limiting reactant in a chemical reaction involving known masses of two reactants, which of the following would be most useful

calculating the mass of a single product formed from each reactant

In the expression of 3CO2, the number 3 and 2 are respectively

coefficient and a subscript

Which of the following expressions is NOT a legitimate conversion factor? a. 28.02g N2 1 mol N2 b. 2.02g H2 1 mol H2 c. 1 mol______ 6.02 x 10^23 atoms d. 1g C______ 6.02 x 10^23 atoms

d. 1g C______ 6.02 x 10^23 atoms

The Kinetic-Molecular theory of gases assumes that the particles of an ideal gas are separated by great distances. This implies that the gas particles are considered to have no definite

density

The formation of frost is an example of

deposition

The spontaneous mixing of the particles of two substances caused by their random motions is called?

diffusion

According to the Kinetic-Molecular theory, particles of an ideal gas

do not collide and do not attract or repel each other

The passage of gas particles through a small opening is called

effusion

If kinetic energy is neither gained nor lost, a collision is called

elastic

Liquids and gases both flow; therefore they are called

fluids/liquids

Pressure

force/area

For the reaction: N2 + H2 --> 2NH3, a chemist must determine how many grams of nitrogen are needed to produce 500 g of ammonia. What is the unknown?

grams of nitrogen

A chemist must determine how many moles of H2 can be produced from 4.7E12 g of H2O in the reaction: 2Na + 2H2O --> 2NaOH + H2 What is the given?

grams of water

Under which conditions does a real gas behave very much like an ideal gas?

high temperatures and low pressure

Which of the following expressions related the kelvin and Celsius temperature scales?

k= 273+C*

The participation of reactants in a chemical reaction is restricted by the

limiting reactant

In the reaction: CH4 + 2O2 --> CO2 + 2H2O; a mass of 125g CH4 is reacted with excess oxygen. The expression 125g CH4 x 1 mol CH4 x 2 mol H2O x 18.02g H2O 16.05g CH4 1 mol CH4 1 mol H2O Is used to calculate:

mass of water produced

Most manometers and barometers contain

mercury

A balanced chemical equation allows one to determine the

mole ratio of any two substances in the reaction