Last one I promise! Thankyou for bearing with me. This seems simple enough, but chemistry genuinely makes me feel ed so I appreciate reassurance.

How many molecules of CH4 are there in 48.2g of the compound?

I'm assuming that I should just divide 48.2 g by the molar mass of CH4 which is 16.05g, and it calculates to 3 mols. Is this correct?

If the question asked for moles, ok but it asked for molecules.

There are 6.022 x 10^23 molecules in a mole so 3.01 x 6.022 x 10^23 = # molecules. I would use 3.01 and not 3 since you have 3 significant figures in 48.2 and 4 in 16.05.

Thankyou very much for clearing that up.

The density of mercury is 13.54 g/cm3. Suppose you need 40 gm of mercury for an experiment. What volume of mercury do you need?

No problem at all! I'm here to help.

To determine the number of molecules of CH4 in 48.2g of the compound, we need to follow a few steps:

1. Calculate the molar mass of CH4:
- The molar mass of carbon (C) is 12.01 g/mol.
- The molar mass of hydrogen (H) is 1.01 g/mol.
- Since there are four hydrogen atoms in one molecule of CH4, the total molar mass is:
Mass of carbon + (Number of hydrogen atoms x molar mass of hydrogen) = 12.01 g/mol + (4 x 1.01 g/mol) = 16.05 g/mol.

2. Determine the number of moles of CH4:
- To find the number of moles, divide the given mass by the molar mass.
Moles = Mass (g) / Molar mass (g/mol) = 48.2 g / 16.05 g/mol ≈ 3 moles.

Therefore, your calculation is correct. There are approximately 3 moles of CH4 in 48.2g of the compound.

To find the number of molecules in 3 moles of CH4, we need to use Avogadro's number, which is approximately 6.022 x 10^23 molecules/mol. Multiplying the number of moles by Avogadro's number will give us the number of molecules:

Number of molecules = Number of moles x Avogadro's number
= 3 mol x 6.022 x 10^23 molecules/mol ≈ 1.807 x 10^24 molecules.

Therefore, there are approximately 1.807 x 10^24 molecules of CH4 in 48.2g of the compound.