Atoms
Balance the chemical equation:
C3H8 + O2 → CO2 +H2O
C3H8 + 5O2 → 3CO2 +4H2O
How many water molecules are there in 0.5 moles of water?
3 x 1023 molecules of water
What kind of electromagnetic wave is something at a wavelength of 4.32 pm
(note pm is picometer)
X-ray spectrum
What are the elements in column 7A of the periodic table called?
Halogens
To what volume should you dilute 133 mL of an 7.90 M CuCl2 solution so that 51.5 mL of the diluted solution contains 4.49 g CuCl2?
Molar Mass of CuCl2: 124.45 g/mol
You should dilute the 133 mL of an 7.90 M CuCl2 solution to 1620 mL.
(Find moles of CuCl2 first, then find your M2. Then solve for your V2)
What is the mass percentage of sodium in Na3AlF6?
Molar Masses:
Na: 22.990 g/mol
Al: 26.982 g/mol
F: 18.998 g/mol
32.852% Na
How many moles are there in 50.0 grams of Pb?
Molar Masses:
Pb: 207.2 g/mol
0.241 moles
What is ionization energy?
Minimum energy required to remove an electron completely from the gaseous atom or ion
What is the chemical formula for magnesium phosphide?
Mg3P2
53.4 mL of a 1.50 M solution of NaCl is on hand, but you need some 0.800 M solution. How many mL of 0.800 M can you make?
(1.50 mol/L) (53.4 mL) = (0.800 mol/L) (x)
x = 100. mL
An 8.29-gram sample of lanthanum oxide is found to contain 7.08 grams of lanthanum and 1.21 grams of oxygen. Calculate the mass percentages of lanthanum and oxygen in lanthanum oxide.
85.4% La
14.5% O
The density of a liquid is 0.997044g/mL, what is the volume (in L) of a 60.3 kg sample?
60.5 L
A photon has an energy of 3.57×10-20 J. What is the frequency of this photons? Give your answer in Hz.
5.39 x 1013 Hz
What is the name of SF6?
Sulfur Hexafluoride
If you dilute 175 mL of a 1.6 M solution of LiCl to 1.0 L, determine the new concentration of the solution.
M1V1 = M2V2
(1.6 mol/L) (175 mL) = (x) (1000 mL)
x = 0.28 M
Calculate the molecular mass of C6H8O6 (vitamin C)
Molar Masses:
C: 12.011 g/mol
H: 1.008 g/mol
O: 15.999 g/mol
176.124 g/mol
The molar mass of SO3 (sulfur trioxide) is 80.07 g/mol. How many molecules of SO3 are in 0.0780 kg of SO3?
5.87 x 1023
To ionize an electron in the n=4 shell of a hydrogen atom, What is the wavelength (in unit nm) of a photon required to achieve this?
1458nm
What is the chemical formula for nitrogen dioxide?
NO2
100.0 mL of 2.500 M KBr solution is on hand. You need 0.5500 M. What is the final volume of solution which results?
(2.500 mol/L) (100.0 mL) = (0.5500 mol/L) (x)
x = 454.5 mL
How many protons, neutrons, and electrons are in 2068Ca2+
20 protons, 48 neutrons, 18 electrons
If there are 6.40 x 102 acres in a square mile, calculate how many square meters there are in an acre. (Give 3 sig figs)
Other conversion factors:
1 mi = 5280 ft
12 in = 1 ft
2.54 cm = 1 in
4.05 x 103 m2
A metal surface whose work function is 7.20×10-20 J is exposed to light with a wavelength of 200.0 nm. Is this enough to eject electrons from the metal surface? Give the Energy of the photon
(hint Ephoton > Eo is when there is sufficient energy from light to bump off an electron)
Yes, 9.93 x 10-19 J
What is the name of BaO?
Barium Oxide
You need to make 10.0 L of 1.2 M KNO3. What molarity would the KNO3 solution need to be if you were to use only 2.5 L of it?
(x) (2.5 L) = (1.2 mol/L) (10.0 L)
x = 4.8 M