A+ Answers



which of the following elements would exhibit the greatest shielding effect?

A. lithium

B. potassium

C. rubidium

D. sodium

Which of the following are not grouped according to similar chemical properties?

A. Gold, silver, copper

B. iron, copper, ruthenium

C. ruthenium, indium, palladium

D. cobalt, iron, nickel

which of the following would not increase the rate of most reactions?

A. removing an inhibitor

B. lowering the concentration

C. adding a catalyst

D. increasing the temperature

which of these lists the energies of the sub levels, from highest to lowest?

A. s>p>d>f

B. d>f>s>p

C. d>p>s>f

D. f>d>p>s

 based on electronegativity differences, between which two elements will a bond results in a highly unequal sharing of electrons?

A. lead and sulfur

B. nitrogen and oxygen

C. chlorine and lithium

D. aluminum and chlorine

what statement does not accurately describe the following equation?

C6H12O6 + 6O2 right pointing arrow 6H2O + 6CO2 + energy

A. the reaction is endothermic

B. this reaction releases energy

C. eighteen atoms of oxygen are found as both part of the reactants and the products

D. oxygen is a reactant

what is the major element per mass in NaOH?

A. all elements contribute the same mass

B. sodium

C. oxygen

D.Hydrogen

the least common form of matter on earth is

A. amorphous solid

B. plasma

C. liquid crystal

D. gas

which of the following devices can measure only atmospheric pressure?

A. pressure gauge

B. barometer

C. tire gauge

D. Mercury Tube

what is the volume of 0.04 mol of a gas at 0.9 kPa and 20 degree C

A. 108L

B. 7.4L

C. 87.5L

D. 14.8L

how many silver (Ag) atoms are in a silver bar that is 20.0 g ?

A. 6.02 3 10^23 Ag atoms

B. 1.1 3 10^23 Ag atoms

C. 1.3 3 10^27 Ag atoms

D.1.8 3 10^23 Ag atoms

a container of gas has a volume of 3.5 L and a pressure of 0.8 atm. Assuming the temperature remains constant, what volume of gas would result if the pressure was 0.5 atm?

A. 5.6 L

B. 0.2 L

C. 2.2 L

D. 1.8 L

the rate of evaporation is affected by all of the following except

A. the humidity

B. the type of solid evaporating

C. the area of the surface

D. the temperature

what is the molecular mass of potassium hydrogen carbonate (KHCO3)?

A. 116 g/mol

B. 68 g/mol

C. 100g/mol

D. 84 g/mol

how many moles are contained in a 4.67 L sample of gas at 30 degree C and 199 kPa?

A. 0.37 mol

B. 1.7 mol

C. 11.8 mol

D. 3.7 mol

which of the following is true regarding phase changes?

A. sublimation is the same as boiling

B. melting is the reverse of deposition

C. condensation is the reverse of evaporation

D. freezing is the same as sublimation

what is the molarity of a solution with a volume of 974mL containing 17 g of CuSO4?

A. 0.0001 M CuSO4

B. 9.66M CuSO4

C. 2.79M CuSO4

D. 0.109M CuSO4

which of the following is not an application that uses chemiluminescent reactions?

A. tarnish polish

B. Lightning

C. Light sticks

D. criminal investigations using luminal to detect blood

how many steps are required to completely ionize a triprotic acid?

A. one

B. two

C. three

D. four

A 25mL sample of 0.160M solution of NaOH is titrated with 17 mL, of an unknown solution of H2SO4. what is the molarity of the sulfuric acid solution?

A. 0.117M H2SO4

B. 0.235M H2SO4

C. 0.002M H2SO4

D. 0.004M H2SO4

_______ is often utilized in reactions involving bleach.

A. CO2

B. CI2

C. O2

D. OCI2

which element is reduced in the reaction below?

BaCL2(aq) + Na2SO4(aq) right pointing arrow NaCI(aq) + BaSO4(s)

A. Na

B. Cl

C. none

D. Ba

which of the following statements about the pH scale is true?

A. acids, which have higher concentrations of hydronium ions than bases, are found from 0 and up to 7

B. bases, which have higher concentrations of hydronium ions than acids, are found from 0 and up to 7

C. acids, which have a lower concentration of hydronium ions than bases, are found from 14 and down to 7

D. bases, which have higher concentration of hydronium ions than acids, are found from 14 and down to 7

the fact that water requires a large amount of energy before its temperature changes is the result of water’s

A. high specific heat

B. ability to exhibit surface tension

C. ability to demonstrate capillarity

D. lower density as a solid

all the following are necessary parts of a neutralization reaction except

A. an indicator

B. an acid

C. water

D. a salt

which of the following is not an example of lipid?

A. ribose

B. oils

C. fats

D. waxes

in an exothermic reaction, the water will _______ in a calorimeter

A. absorb heat

B. drop in volume

C. drop in temperature

D. release heat

all the following are steps included in linking amino acids to form chains except

A. removing a hydrogen from the amino group

B. removing the hydroxyl part of the amino group

C. using a peptide bond to connect the amino acids

D forming water

which of the following is not a reason that power plants are unable to achieve 100 percent efficiency?

A. entropy increases

B. the amount of work obtained from a process never has work needing to go into it.

C. heat is often a waste product

D. not all energy is converted heat from chemical reactions into useful work

______ is the radioisotope commonly used to map a human’s circulatory system.

A. technetium-99m

B. Carbon-14

C. cobalt-60

D. iron-59

which of the following is true regarding activation energy?

A. it is required only in exothermic reactions

B. it does not hold up a reaction from starting

C. this energy usually comes in the form of light or heat

D. it is required only in endothermic reactions

_______ are the best starting materials for making organic compounds with varying functional groups

A. aldehydes

B. Hydrocarbons

C. carboxylic acids

D. alcohols

which of the following is true regarding chemical and nuclear reactions?

A. both processes are always affected by changes in temperature, pressures, and catalysts

B. both processes involve breaking bonds

C. both processes involve subatomic particles

D. both processes are associated with large changes in energy

in which set of conditions would result in a spontaneous reaction?

A. an endothermic reaction; an increase in entropy; at low temperatures

B. an exothermic reaction; an increase in entropy; at any temperatures

C. an exothermic reaction; an decrease in entropy; at high temperatures

D. an endothermic reaction. an decrease in entropy; at any temperatures

which of the following accurately describes the properties of DNA and RNA?

A. DNA and RNA are made up of repeating nucleotides

B. DNA and RNA use the same sugar

C. DNA and RNA use the same four bases

D. DNA and RNA have identical structures

all of the following are true regarding alcoholic fermentation, except that alcoholic fermentation

A. does not require oxygen

B. produces as much energy as cell respiration

C. uses glycolysis

D. produces ethanol