First week stuff (Dimensional Analysis etc.)
Without writing or using a calculator: how many cm are in 5 km?
5x105 cm (500,000 cm)
Without writing or using a calculator, tell me what 1/2 a mole is equal to (one person goes).
3.011 x 1023
Name these two compounds perfectly: KF and CaBr2
potassium fluoride and calcium bromide
Which has a greater volume under identical conditions: 1 mole of hydrogen gas (H2) or 1 mole of xenon gas (Xe)?
They're the same volume
What group of people decides what all the various numbers on the periodic table should be?
Swedish Lawyer Chemists
How many milliseconds long is today's class?
60 minutes * (60 seconds/1 min) * (1000 ms/1 second) = 3,600,000 ms
How many atoms are in a 0.0040 gram sample of Bk (#97)?
9.8 x 1018 atoms
Give the formula for iron (III) sulfate
Fe2(SO4)3
A 4.00 mL sample of fluorine gas at 36.2°C and 2.14 atm is heated to 37.8°C, and the pressure changed to 1.02 atm. What volume does the gas occupy at the new temperature and pressure?
0.00844 L
Draw me the Lewis structure and VSEPR diagram for SCl2. Indicate bond angle.
I'll draw it now
The density of gold is 19.3 g/cm3. How many kg of gold would I need to fill my 1 L water bottle?
19.3 kg
How many molecules are in 86 kg of hydrazine (N2H4), an early jet fuel?
1.6 x 1027 molecules
Name this compound: Co(PO4)2
Cobalt (VI) phosphate
The reaction of a copper penny with nitric acid results in the formation of a red-brown gaseous compound containing nitrogen and oxygen. A sample of the gas at a pressure of 727 mmHg and a temperature of 18°C weighs 0.289 g in a flask with a volume of 157.0 mL. Calculate the molar mass of the gas and suggest a reasonable chemical formula for the compound.
Remember: molar mass = dRT/P
~46 g/mol; NO2
2 ZnS (s) + 3 O2 (g) → 2 ZnO (s) + 2 SO2 (g)
ΔH = -878 kJ/mol
What mass of solid ZnS, in kilograms, must react according to the equation above in order for 5.41 x 103 kJ of heat to be released?
1.2 kg
Convert 2300 mL to m3
0.0023
How many mL does 3.0 x 1023 molecules of HF occupy? The density of HF is 0.97 g/mL
10 mL
Give the balanced equation for when sodium nitrate reacts with lead (II) iodide.
2NaNO3 + PbI2 --> 2NaI + Pb(NO3)2
The following reaction is utilized in automobile airbag systems: 2NaN3 (s)→ 2Na(l) + 3 N2 (g)
How many grams of NaN3 are needed to produce 19.5 L of nitrogen gas at 31.5°C and 775 torr?
34.5 g
Find the pH of a 1.5 M solution of nitrous acid (HNO2, K = 7.2 x 10-5).
Haven't solved this yet I'll do it at the board
1 blorp is equivalent to 4 plumbuses. 3 plumbuses are equivalent to 7 gazorps. 1.5 gazorps are equivalent to 15 shmeezles. 5 shmeezles are equivalent to 2 zargos.
How many zargos are contained in 3 blorps?
112
An unknown compound is composed of 36.5% sodium and 38.1% oxygen by mass, with the remainder being sulfur. If the molar mass of the compound is about 126 g/mol, determine the molecular formula of the compound.
Na2SO3
When a student heated a hydrate of lithium acetate hydrate, LiCH3COO • x H2O the following lab data was collected: mass of empty evaporating dish: 14.68 g
mass of same dish with hydrate: 28.56 g mass of same dish with LiCH3COO: 23.61 g
Find the precise formula for the hydrate.
LiCH3COO*2H2O
A 1.75 g sample of magnesium and iron is added to dilute hydrochloric acid, producing 1.1 L of hydrogen gas at 28.5 0C and 765 mm Hg. What is the percent composition (by mass) of the original sample to the nearest whole number?
Mg (s) + 2 HCl (aq) → MgCl2 (aq) + H2 (g)
Fe (s) + 2 HCl (aq) → FeCl2 (aq) + H2 (g)
67% Fe roughly
The specific heat of titanium metal is 0.54 J/g•°C. In an insulated calorimeter, a 265 gram piece of titanium metal originally at 285°C was added to 645 grams of water originally at 26°C. Determine the final temperature of the titanium-water mixture.
39oC