chemistry exam 3

NO Nitrogen ox # ___Oxygen ox # ___

+2 -2

N2O5 Nitrogen ox # ___Oxygen ox # ___

+5 -2

Applying this rule to PO43- says; (P ox #) + 4(O ox #) = -3 What is the oxidation number for oxygen in PO43-?

-2 no

Assign oxidation numbers to each element in SO2. 1(S ox #) + 2(O ox #) = 0 (S ox #) + 2(-2) = 0 (S ox #) - 4 = 0 S ox # = +4 What is the oxidation number of each oxygen in SO2? What is the oxidation number of sulfur in SO2?

-2, +4

What is the oxidation number of oxygen in PO43-?What is the oxidation number of phosphorus in PO43-?

-2, +5

Nitrogen ox # ___Hydrogen ox # ___

-3, +1

Convert 1 x 10-4 M NaOH to a decimal number.

0.0001 M NaOH

Which pH (1 or 3) has the highest hydrogen ion concentration?

1

Determine the molar mass (weight) of each substance in thisreaction: 1 mole N2 = ____ grams 3 moles H2 = ____ grams 2 moles NH3 = ____ grams

1 mole N2 = ___28_ grams 3 moles H2 = __6__ grams 2 moles NH3 = __34__ grams

Acid] x [Base] = 1 x 10-14 [H+] x [OH-] = 1 x 10-14What is the product of acid concentration times base concentration?

1 x 10^-14

[H+] x [OH-] = 1 x 10-14

1 x 10^-14

Strong acids ionize ______ % to release hydrogen ions in water.

100 weak = 5

The molar mass of sugar (C12H22O11) is 342 g/mole. Thus, the mass of 3 moles of sugar is ____ grams.

1026

What is the formula weight of Ca(NO3)2?

164 amu

A 2 M (molarity) solution of NaOH contains ___ moles of NaOH in a liter.

2

Ca5(PO4)3F + 5H2SO4 + 10H2O → 3H3PO4 + 5CaSO4·2H2O + HFBesides phosphoric acid, this reaction produces gypsum(CaSO4·2H2O) and hydrofluoric acid (HF).How many other products are produced from making phosphoric acid?

2

The molarity of a solution containing 4 moles of HCl in 2 liters of solution is ___ M HCl.

2

How many conditions must be met for a reaction to occur?

3

How many acidic hydrogens does phosphoric acid have?How many hydrogen ions will phosphoric acid release in water?

3,3

Write 4660 in scientific notation.

4.66 x 10^3

What is the mass of 3 moles of water (H2O)?

54

NaCl Formula weight = _____ amu (round to nearest tenth) Molar Mass = _____ grams

58.5

A catalyst will increase the rate of a chemical reaction.

A catalyst is a substance that increases the rate of a chemical reaction but does not get consumed by the reaction.

H2SO4 + Ba(OH)2 → water + salt The salt formula for this acid-base reaction is _____.

BaSO4

HNO3 + Ca(OH)2 → water + salt The salt formula for this acid-base reaction is ______.

Ca(NO3)2

The acid anion formula is Cl- The base cation formula is Ca2+ The salt formula is _____.

CaCl2

MOLAR MASS is the mass in grams of one mole of a substance that is equal to its ATOMIC or FORMULA WEIGHT.

Fluorine (F) Atomic weight = __19___ amu Molar Mass = __19___ grams

MOLAR MASS is the mass in grams of one mole of a substance that is equal to its ATOMIC or FORMULA WEIGHT.

HCl Formula weight = ___36.5__ amu (round to nearest tenth) Molar Mass = 36.5_____ grams

Which periodic-table groups do the metals in the strong bases come from?

IA IIA

What is the formula for the salt?

KI

What is the molar mass for the following compounds?

Na2SO4 __142___ g NaHCO3 ___84__ g C2H6O __46___ g O2 ___32__ g

H2SO4 + NaOH → water + salt The acid anion _____. The base cation ____. The salt formula for this acid-base reaction is ______.

SO4(2-), Na+, Na2S04

1. Hydrogen ions from the acid react with hydroxide ions from the base to form WATER.2. The anion part of the acid and the cation part of the base form a SALT.

The anion part of the acid is NO3- The cation part of the base is (K+

The FORMULA WEIGHT of a compound is the sum of the individual atomic weights of the elements in the formula.For example the formula weight of H2O is 18 amu. H: 2 x 1 amu = 2 amu O: 1 x 16 amu = 16 amu Total: 18 amu

The formula weight of CO2 is __44_amu. Work:C: 1 x 12amu = 12amuO: 2 x 16amu = 32amuTotal: 44amu

Water (H2O) has an atomic weight of 18 amu and a molar mass of 18 grams. This means that one mole of water has a mass of 18 grams. Therefore, if you have two moles of water you will have 36 grams of water (18 x 2). The mass of a substance is equal to its molar mass times the number of moles.

The molar mass of a substance times the number of moles will equal the mass of the substance. (true

When the name of a compound ends in 'ic' the compound is an

acid

A substance that releases hydroxide ions when dissolved in water is a

base

Al(OH)3

base

What are the predominant forms of energy produced when;• a green plant grows?

chemical

NaOH sodium hydroxide KOH potassium hydroxide Ca(OH)2 calcium hydroxide NH4OH ammonium hydroxide

common bases Many common bases contain the OH- polyatomic ion in their formula.

Chemical reactions always produce (different, same) substances.

diff

Concentration of an acid (does, does not) determine if an acid is strong or weak.

does not

What are the predominant forms of energy produced when;• water out of a dam runs a generator?

electrical

A reaction which produces heat is an ________ reaction.

exothermic

All chemical reactions have the same activation energy. (true, false)

f

solids are more likely to react

gas

What are the predominant forms of energy produced when;• a log is burned in a fireplace?

heat, light,

Hydrogen ions react with water to form ______ ions.

hydronium

base releases

hydroxide

Since it is harder to remove each succeeding hydrogen, each hydrogen is (less, more) acidic.

less

Acidic solutions have (more, less) hydrogen ions than hydroxide ions.

more

asic solutions have (more, less) hydroxide ions than hydrogen ions.

more

H2SO4 sulfuric acid HCl hydrochloric acid HNO3 nitric acid H3PO4 phosphoric acid HC2H3O2 acetic acid

most common acids

Are hydrogens bonded to carbon atoms acidic?

no

Is a hydrogen atom acidic when it is bonded to a carbon atom?

no

Cleaning solutions are basic because they react with _____ materials.

organic

The speed at which reactants change into products is known as the

reaction rate

NH4NO3

salt

Atoms need sufficient energy to overcome electron repulsion which keeps them apart. (true, false)

t

For a chemical reaction between two molecules to happen the molecules must collide. (true, false)

true

n acid-base reaction will always produce w____ and s____.

water salt