Moles
Which of the following does the unit mole represent?
1. Density of particles
2. Kind of particles
3. Number of particles
4. Reactivity of particles
3. Number of particles
What is the mass of a mole of O2 in grams?
32 grams
in balanced equations, what do the coefficients represent?
The mole ratios of reactants and products.
How do you find the percent of an element in a compound?
Divide the total mass of an element by the total mass of the compound and multiplied by 100.
A hydrated crystal is one in which…
1. water molecules are part of the crystal
2. water molecules have been removed
3. hydrogen molecules are part of the crystal
4. hydrogen molecules have been removed
1. water molecules are part of the crystal
which of the following is the mass of one mole of substance equal to…
1. The atomic number in grams
2. The mass of the most common isotope in grams
3. The gram formula mass
4. The mass of 22.4 L of any substance
3. The gram formula mass
The mass of four moles of CO2 is…
176 grams
Given the balanced equation representing a reaction:
2CO (g) + O2 (g) —>2CO2 (g)
What is the mole ratio of CO(g) to CO2(g) in this reaction
1:1
What is the percent by mass of carbon in CO2?
27%
What is the gram formula mass of Ca(OH)2?
74g
One mole of carbon and one mole of neon both have the same…
Number of particles
The mass of a mole of Ca(OH)2 is…
74 grams
Given the equation
Mg + 2HCl --> MgCl2 + H2
How many moles of hydrogen chloride are needed to react with 0.5 mol of magnesium?
1 mol
What is the percent by mass of sulfur in sulfur dioxide?
50%
What is the gram atomic mass of zinc?
65 grams
What is the total number of moles in 80 g of C2H5Cl (gfm: 64.5 grams)?
1.24
The mass of a mole of H2X is 34 g than X must be what element?
Sulfur
Consider the following equation
2C2H6 + O2 —> 4CO2 + 6H2O
When four moles of C2H6 are burned the number of moles of CO2 produced will be?
8 mol
What is the percent by mass of oxygen in Fe2O3? (Formula mass: 160g)
30%
Which substance has the greatest molecular mass?
1. H2O2
2. NO
3. CF4
4. I2
4. I2