What compound is represented by the name:
Pentabromine hexafluoride
Trisulfur triphosphide
Nitrogen monoxide
Br5F6
S3P3
NO
What is the molar mass of the following substances:
Fe
AlF3
ClO2
55.845 g/mol
83.976 g/mol
67.451 g/mol
The mass of a sample of brass is 2.50 g. If brass has a density of 8.47 g/cm3, what is the volume of this sample?
0.295 cm3
2Na + Cl2 -> 2NaCl
Sketch the cathode-ray tube experiment and state what it revealed about the nature of the atom.
The atom has a negative part that is easily removed.
What compounds refers to the following compounds:
Nickel(II) oxide
Lithium nitride
Lead(III) sulfide
NiO
Li3N
Pb2S3
What is the percent composition of oxygen in the following compound:
KBrO4
34.971%
How many moles are in a 200.00000000 g sample of sodium fluoride?
4.76327 mol
__Ca + __H2O -> __Ca(OH)2 + __H2
2Ca + 2H2O -> 2Ca(OH)2 + H2
Which of the following becomes a cation? Does it gain or lose electrons when forming an ion?
Cs
I
Pb
Ar
Lose
Which of the compounds is incorrectly named?
Dicarbon trioxide
Magnesium iodide
Ditellurium nitride
Ammonium Sulfate
Ditellurium mononitride
If a molecule has an empirical formula of NH2, which of the following cannot be its molecular weight? Why
16.023 amu
48.069 amu
88.127 amu
128.184 amu
88.127 amu
An average man requires about 2.0 mg of riboflavin (Vitamin B12) per day. One slice of cheese contains 5.5 µg of riboflavin. How many slices of cheese would a man have to eat per day if it were his only source of riboflavin?
360 slices
__C4H10 + __O2 → __CO2 + __H2O
2C4H10 + 13O2 → 8CO2 + 10H2O
How many atoms are in the molecules? How many nitrogen atoms?
13 atoms
3 nitrogen atoms
What is the molar mass of the compound calcium phosphide?
Ca3P2
3(40.078) + 2(30.974)
182.182 g/mol
What is the empirical formula of a compound with a molecular weight of 112 amu and the following percent composition:
42.84% C 49.96% N 7.191 % H
C4N4H8
How many grams is present in exactly 1 atom of molybdenum?
1.529 x 10-20 g
__C3H8 + __N2 -> __C + __H2 + __N2
2C3H8 + 7N2 -> 6C + 8H2 + 7N2
How many protons, neutrons, and electrons does the following isotope have:
242Pu4+
Protons: 94
Neutrons: 148
Electrons: 90
What is the name of the following compounds?
Fe2(SO4)3
U(CO3)3
Iron(III) sulfate
Uranium(VI) carbonate
One more diifficult question
Aswer
Diamonds are measured in carats and 1 carat = 0.200 g. The density of diamond is 3.51 g/cm3 . A diamond is dropped into a graduated cylinder filled with 30 mL of water and the final volume is measured to be 35 mL. How many carats is the diamond?
88 carats
__C6H12 + __NaCl→ __C + __HCl + __Na2C2O4
C6H12 + 6NaCl → 6C + 6HCl + 3Na2C2O4
In beta decay, a neutron in an unstable nucleus becomes a proton. If carbon-14 undergoes beta decay twice, what isotope is produced?
Oxygen-14