Chapter 1-4
State the number of significant digits: 0.003068 m and 75,000.0 m
0.003068 m has 4 and 75,000.0 m has 6
Name this ion: NO3-
Nitrate
Balance the following equation: Al + Zn2+ → Al3+ + Zn
2Al + 3Zn2+ → 2Al3+ + 3Zn
Write the complete orbital box diagram, electron configuration, and noble gas notation for: Sr2+, Z = 38
On board
How much KBr must be used to prepare 250mL of 4.4%(w/v) solution?
11 grams of KBr
Express the following numbers in their equivalent standard notational form: 123,876.3 and 0.000000000000211
123,876.3 (1.23876 x 105) and 0.000000000000211 (2.11 x 10-13)
Calculate the percent by mass of each element in the following compounds: Al2O3
52.9 % of Al and 47.05 % of O
Predict whether a precipitate will form when aqueous solutions of the following
compounds are mixed. If a precipitate will form, write its formula, and write a net ionic
equation. Identify the spectator ions:
Pb(NO3)2(aq) + K2SO4 (aq) →
Answer on board
Arrange the elements the set in order of increasing ionization energy (by using only the periodic table): N, F, O, C
C < N < O < F
How do we prepare 3.9L of a 0.012M aqueous solution of NaHSO3?
M = n/v
Go from mole -> gram and add 4.9 grams to 3.9 liters
What is the density of mercury (13 .6 g/cm3) in units of kg/m3?
1.36 x 104 kg/m3
Calculate the number of moles of indicated substance in the following sample: 34.6 g of C6 H12 O6
0.192
Given the reaction 2HgO(s) → 2Hg(l) + O2(g). In an experiment, starting with 632g of mercury(II) oxide (HgO) gave 411g mercury. What the percent yield in this experiment?
70.2%
Draw the Lewis structure for: NH4+
On board
The Ksp value for solid Al(OH)3 is 3.7×10-15 at 25°C. Calculate the solubility of Al(OH) 3
in water at 25°C.
2.4 x 104 M
What is the atomic number and mass number of this element?
106 protons, 106 electrons, 150 neutrons
Sg
Calculate the number of molecules present in the following sample: 12.3 g of CaCl2
6.62 x 1022 molecules
Is this reaction exothermic or endothermic? Why?
2HgO + 43.4 Kcal → 2Hg + O2
When energy is absorbed in an endothermic reaction
A balloon contains 4 moles of an ideal gas with a volume of 5.0 L. If an additional 8
moles of the gas is added at constant pressure and temperature, what will be the final volume of the balloon?
15 L
Calculate pH of a buffer solution prepared from 0.1 mole of formic acid (HCOOH) and
0.02 mole of sodium formate (HCOONa) diluted to 1L. (pKa of formic acid is 3.75)
3.05 pH
Provide the name/formula for the following compounds: Fe(ClO2)3 and Aluminum dihydrogen phosphate
Fe(ClO2)3 = Iron (III) chlorite
Aluminum dihydrogen phosphate = Al(H2PO4)3
For the reaction 2HgO(s) → 2Hg(l) + O2(g) how many molecules of Hg are produced by
using 367g HgO?
1.02 x 1024 molecules of Hg
For the reaction 4Fe(s) + 3O2 (g) → 2Fe2O3 (s) ∆H = -1652 kJ per mole of Fe2O3 formed:
Calculate the quantity of heat released when 2.4 g of Iron is oxidized.
-35.5 kJ
Calculate the energy (in kJ) required to melt 67g of ice, at its normal melting point
(0.00°C)? (molar heat of fusion of ice is 6.02 kJ/mol)
22.4 kJ
At a given temperature, an equilibrium mixture of the reaction 2NO(g) + O2 (g) ↔ 2NO2(g)contains 0.090 moles NO, 0.120 moles of O2 , and 0.060 moles of NO2 in a 3.00 liter container. Find the value of K
Ka= 11.11