1. how many moles are in 3.4 x 1024 molecules of hcl?
2. how many grams are in 2.59 x 1023 formula units of al2o3?
3. how many grams are in 9.05 x 1023 atoms of silicon?
4. if you had 7.00 moles of pto2, how many grams would you have?
5. how many moles are in 29.2 l of oxygen gas at stp?
6. what is the volume (liters) of 75.8 g of n2 at stp?
show work for each one .

1. How many moles are in 3.4 x 10²⁴ molecules of HCl?

if there are 6.022 × 10²³ molecules in 1 mole of HCl

then there are 3.4 × 10²⁴ molecules in X moles of HCl

X = (3.4 x 10²⁴ × 1) / 6.022 × 10²³ = 5.6 moles of HCl

2. How many grams are in 2.59 x 10²³ formula units of Al₂O₃?

 if there are 6.022 × 10²³ units in 1 mole of Al₂O₃

then there are 2.59 × 10²³ units in X moles of Al₂O₃

X = (2.59 x 10²³ × 1) / 6.022 × 10²³ = 0.43 moles of Al₂O₃

number of moles = mass / molecular weight

mass = number of moles × molecular weight

mass of Al₂O₃ = 0.43 × 102 = 43.86 g

3. How many grams are in 9.05 x 1023 atoms of silicon?

if there are 6.022 × 10²³ atoms in 1 mole of silicon

then there are 9.05 × 10²³ atoms in X moles of silicon

X = (9.05 x 10²³ × 1) / 6.022 × 10²³ = 1.5 moles of silicon

mass = number of moles × molecular weight

mass of silicon = 1.5 × 28 = 42 g

4. If you had 7.00 moles of PtO₂, how many grams would you have?

mass = number of moles × molecular weight

mass of PtO₂ = 7 × 227 = 1589 g

5.How many moles are in 29.2 L of oxygen gas at STP?

At standard temperature and pressure (STP) we may use the  following formula:

number of moles = volume (L) / 22.4 (L / mol)

number of moles of oxygen = 29.2 / 22.4 = 1.3

6. What is the volume (liters) of 75.8 g of N₂ at STP?

number of moles = mass / molecular weight

number of moles of N₂ = 75.8 / 28 = 2.7 moles

At standard temperature and pressure (STP) we may use the  following formula:

number of moles = volume (L) / 22.4 (L / mol)

volume = number of moles × 22.4

volume of N₂ = 2.7 × 22.4 = 60.48 L

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.