Misc.
Conversions
Empirical Formulas
Molecular Formulas
Mass Spectroscopy
100
What is this lab material?
Erlenmeyer Flask
100
What is the molar mass of water?
18.015 g/mol
100
What is an empirical formula?
the atoms of a molecular formula shown in the smallest ratio
100
What is a molecular formula?
the chemical formula with atoms in the ratios they actually occur
100
What is an isotope?
An atom with a different number of neutrons.
200
How do you convert from moles of Carbon to Atoms of Carbon. Be VERY specific.
Use the molar mass of Carbon, which is 12.011 g/mol
200
How many moles are there in 76.44 g H3PO4?
0.78 mol
200
What is the empirical formula for carbon monoxide?
CO
200
What is the molecular formula for copper II sulfate?
CuSO4
200
What does a mass spectrometry graph measure?
The % abundance of isotopes of an element.
300
Which scientist is responsible for our use of the mole?
Avagadro
300
How many grams are in 6.2 mol BF3?
420.36g
300
What is the empirical formula for glucose? (C6H12O6)
CH2O
300
What are the steps you must follow to find the molecular formula from % mass?
find the empirical formula (using the "rhyming steps") calculate the empirical formula mass divide the molar mass by the empirical formula mass multiply the empirical formula by this number
300
What is this element likely to be called?
Boron (B)
400
What is this lab material?
Evaporation Dish
400
How many molecules are in 35.4 mol CO2?
2.13x10^25 molecules
400
What are the steps used in order to determine the empirical formula of a molecule from the percent make up?
percent to mass, mass to mole, divide by small, multiply by whole
400
Find the molecular formula for a compound whose molar mass is 186.072 and empirical formula is CH2O3.
C3H6O9
400
Which element is this likely to be?
Zirconium (Zr)
500
Find the answer to this problem with the correct number of significant figures.
How many TOTAL moles of NaCl and H2O are present when 12.34 grams of NaCl are added to 3.9572 moles of H2O?
4.21 moles of NaCl + H2O
500
Why can't you convert directly from particles to grams(and vice versa)?
The mole is a representation of the number of particles in a sample that a scientist can actually work with. There is a high probability of error if you were to use the mass of a single particle.
500
What is the empirical formula for a compound containing 50.0% C, 5.5% H, and 44.4% O?
C3H4O2
500
What is the molecular formula of a compound containing 62.0% Cr and 38.0%O whose molar mass is 176.3874 g/mol?
Cr2O4
500
Which Element is this most likely to be?
Chlorine (Cl/Cl2)