How many grams of methane (ch4) are present in 5.6 moles of methane gas? (use dimensional analysis) ?

From the periodic table, we can find that:

molecular mass of carbon = 12 grams

molecular mass of hydrogen = 1 gram

Therefore, molar mass of methane = 4 (1) + 12 = 16 grams

Now we need to calculate the mass of 5.6 moles.

Number of moles can be calculated using the following rule:

number of moles = mass / molar mass

This means that:

mass = number of moles x molar mass

mass = 5.6 x 16 = 89.6 grams

There are 89.6 grams of methane in 5.6 moles.

Now, for the volume of the gas:

At standard temperature and pressure conditions, one mole of gas occupies 22.4 liters, we can simply use cross multiplication to find the volume that 5.6 moles occupies as follows:

volume of 5.6 moles = (5.6 x 22.4) / 1 = 125.44 liters