Chemistry help?

you find the molar mass of these elements. if you have you're periodic table, the number below the element name is usually its molar mass. example, hydrogen has molar mass of 1.01. you add the molar masses together for compounds ie. CO2 would be 12.0+2(16.0)=44.0g/mol

for a.

you find molar mass of c5h12, which is about 72.15g/mol

so to find grams, you multiply 1.05 by 72.15, which is 75.8g.

you can do the rest.

When given moles of substance, multiply moles by the molar mass (aka formula mass) of the substance. We calculate the formula mass by ading the atomic mases of all the atoms in the formula. The first one, C₅H₁₂ = (5 x 12) + (12 x 1.01) = 60 +12.12 = 72.1

1. 1.05 mol C₅H₁₂ - 1.05-mol x 72.1-g/mol = 75.7-g C₅H₁₂

2.1.4 mol F₂ - 1.4-mol F₂ x 38.0-g/mol F₂ = 53-g F₂

3. 0.780 mol Ca(CN)₂ - 0.780 mol Ca(CN)₂ x 92.1-g/mol = 71.8-g Ca(CN)₂

4. 7.00 mol H₂O₂ x 34.02-g/mol = 238-g H₂O₂

5. 5.60 mol NaOH x 40.0-g/mol = 224-g NaOH

6. 3.21 x 10⁻² mol Ni x 58.7-g/mol = 1.88-g Ni

To find the molar mass (MM) of these substances, you must first calculate the mass of one mole of each compound. This can be done by referencing the mass of each element in the given compound in the periodic table and adding them accordingly. For example:

a) 1.05 mol C5H12

First, reference the mass of each element in the compound using the periodic table:

Mass of C: 12.011

Mass of H: 1.008

Next, determine the total mass of each element in the compound by multiplying the mass of one atom of each element (i.e., 12.011 for C) by the number of atoms of each element in the compound itself. To determine how many atoms of each element are in the compound, reference the molecular formula. The number in the subscript of each element is the number by which you should multiply the mass of that element. Because you have 5 carbon atoms in each mole of C5H12, multiply 12.011 by 5.

C: 12.011 * 5 = 60.055

H: 1.008 * 12 = 12.096

Total up the masses of each element in the compound:

60.055 + 12.096 = 72.151

So, one mole of C5H12 is 72.151 grams/mole. However, the problem asks for the molar mass of 1.05 mol of C5H12. To find this, simply multiply the mass of one mole of the compound by the number of moles of the compound for which you are trying to find the mass. You can think of this in terms of a percentage problem-- if you got a 10/20 on a test and wanted to know what percentage out of 100 it was, you would solve by setting up the equation 10/20 = x/100 and cross multiplying. So:

(x grams C5H12) (72.151 g C5H12)

---------------------- = ------------------------

(1.05 mol C5H12) (1 mol C5H12)

1.05 mol C5H12 * 72.151 g C5H12 (per 1 mol C5H12) = 75.76 g

So, there are 75.76 g C5H12 in 1.05 mol C5H12.

The rest should be simple to solve following these steps.