CHEM HW QUESTIONS

34.62 mL of 0.1510 M NaOH was needed to neutralize 50.0 mL of an H2SO4 solution. What is the concentration of the original sulfuric acid solution?

0.0523 M

35.0 mL of 0.255 M nitric acid is added to 45.0 mL of 0.328 M Mg(NO3)2. What is the concentration of nitrate ion in the final solution?

0.481 M

Which of the following frequencies of light has the highest energy? 2.5 x 10^10 s^-1 7.0 x 10^13 s^-1 2.3 x 10^14 s^-1 5.0 x 10^14 s^-1 1.4 x 10^15 s^-1

1.4 x 10^15 s^-1

How many core electrons does a chlorine atom have?

10

number of electrons for Al^3+

10

number of protons for Al^3+

13

An aluminum ion, Al3+, has:

13 protons and 10 electrons

Determine the number of moles of water produced by the reaction of 155 g of ammonia and 356 g of oxygen. 4NH3 + 5O2 → 4NO + 6H2O

13.4 moles

Calculate the molar mass of (NH4)2SO4

132.15 g/mol

What mass of sodium nitrate would be produced from the complete reaction of 1.00 mol of lead nitrate? 2 NaCl + Pb(NO3 )2 → 2 NaNO3 + PbCl2

170 g

How many moles of H are in 4.56 moles of NH2NH2?

18.24 moles H

Balance the following and list the coefficients in order from left to right. ___ Cr + ___ H2SO4 → ___ Cr2(SO4)3 + ___ H2

2, 3, 1, 3

How many moles of phosphine (PH3) are produced for every 4.0 moles of hydrogen that react according to the chemical equation below?3H2 + P2 → 2PH3

2.7 moles

Butane is reacted with oxygen gas to form carbon dioxide and water. Write the balanced reaction (omit state symbols (s), (l), (g), (aq), etc.).

2C4H10 + 13O2 → 8CO2 + 10H2O

Which of the following wavelengths of electromagnetic radiation has the highest energy? 450. nm 225 nm 3.50 x 10^-9 m Correct 8.40 x 10^-7 m 2.50 x 10^-5 m

3.50 x 10^-9 m

What volume (mL) of a 0.3428 M HCl(aq) solution is required to completely neutralize 23.55 mL of a 0.2350 M Ba(OH)2(aq) solution?

32.29 mL

What volume (mL) of a 0.2450 M KOH(aq) solution is required to completely neutralize 55.25 mL of a 0.5440 M H3PO4(aq) solution?

368.0 mL

Chlorine gas reacts with phosphorus to produce phosphorus pentachloride. How many grams of PCl5 are produced from 3.5 g of Cl2 and excess P?5Cl2(g) + 2P(s) → 2PCl5(s)

4.1 g

How many moles of NH3 are there in 77.5 g of NH3?

4.55 mol

What is the theoretical yield of PI3 if 48.0 g of I2 are reacted with an excess of phosphorus according to the following chemical equation?2P(s) + 3I2(s) → 2PI3(s)

51.9 g

Phosphorus reacts with iodine as shown in the chemical reaction below. What is the percent yield of the reaction if 28.2 g PI3 is obtained from the reaction of 48.0 g of I2 with excess phosphorus? 2P(s) + 3I2(s) → 2PI3(s)

54.3%

13 N 7 (How many neutrons are in the isotope?)

6

13 N 7 (How many electrons are in isotope?)

7

13 N 7(How many protons are in the isotope?)

7

A 3.682 g sample of KClO3 is dissolved in enough water to give 375. mL of solution. What is the chlorate ion concentration in this solution?

8.01 × 10^-2 M

When 50.0 mL of a 0.3000 M AgNO3 solution is added to 50.0 mL of a solution of MgCl2, an AgCl precipitate forms immediately. The precipitate is then filtered from the solution, dried, and weighed. If the recovered AgCl is found to have a mass of 0.1183 g, what was the concentration of magnesium ions in the original MgCl2 solution?

8.25 × 10^-3 M

How many Cl atoms are in 0.0728 g of PCl3?

9.58 x 1020 Cl atoms

Calculate the mass of 4.50 moles of Ca3PO4

968 g

Name the following compound: Al(NO2)2

Aluminum nitrite

Write the molecular formula of ethanol

C2H5OH

Vanadium(V) oxide reacts with calcium according to the chemical equation below. When 10.0 moles of V2O5 are mixed with 10.0 moles of Ca, which is the limiting reagent?V2O5(s) + 5Ca(l) → 2V(l) + 5CaO(s)

Ca

Give the formula of calcium phosphate

Ca3(PO4)2

24

Carbonic acid, H2CO3, is a weak acid that contributes to the taste and produces the carbon dioxide bubbles in all carbonated beverages. How many valence electrons are used to show the Lewis structure for H2CO3?

What element is oxidized in the following chemical reaction? NiO2 + Cd + 2H2O → Ni(OH)2 + Cd(OH)2

Cd

Name the compound CuSO4

Copper (II) sulfate

Give the formula of copper(II) bromide

CuBr2

The alkali metal elements are found in _______ of the periodic table.

Group 1A

The common constituent in all acid solutions is

H+

Based on the solubility rules, which of the following should be soluble in water? CaSO4 BaSO4 PbSO4 K2SO4 Correct AgCl

K2SO4

which ones are ionic compounds? KCl C2H4 BaCl2 SiCl4 LiF

KCl BaCl2 LiF

Which one of the following pairs are isoelectronic? Mn^2+ and Ar Zn^2+ and Cu^2+ Na^+ and K^+ Cl^- and S K^+ and Cl^-

K^+ and Cl^-

What are the two different ions present in the compound NH4NO3?

NH^4+, NO^3-

Arrange the elements F, P, and Cl in order of increasing electronegativity.

P < Cl < F

Name the following compound: K3PO4

Potassium phosphate

True

Select True or False: The Lewis structure shown here is correct for ammonia (nitrogen trihydride).

True

Select True or False: The structure below depicts the correct Lewis structure for Dichloromethane, CH2Cl2 (an important solvent in synthetic chemistry).

Which of the following are isotopes?

^14C and ^13C

The elements in Group 2A are known by what name?

alkaline earth metals

is BaF2 ionic or molecular?

ionic

is CsCl ionic or molecular?

ionic

is CCl4 ionic or molecular?

molecular

is NF3 ionic or molecular?

molecular

Identify the major ionic species present in an aqueous solution of C6H12O6 (glucose)

no ions are present

The elements known as the halogens are useful as disinfectants. Of the following which is NOT a halogen? Bromine Fluorine Iodine Oxygen Correct Chlorine

oxygen