Calculate the number of molecules in 4grams of oxygen gas
To calculate the number of molecules in a given amount of substance, we can use the concept of molar mass and Avogadro's number.
First, we need to find the molar mass of oxygen gas (O2). The molar mass of oxygen (O) is approximately 16 grams per mole. Since oxygen gas (O2) consists of two oxygen atoms, the molar mass of oxygen gas is 2 * 16 = 32 grams per mole.
Next, we can use the molar mass of oxygen gas and Avogadro's number, which is approximately 6.022 x 10^23 molecules per mole, to calculate the number of molecules in the given mass.
Number of moles of oxygen gas = Mass of oxygen gas / Molar mass of oxygen gas
= 4 grams / 32 grams per mole
= 0.125 moles
Number of molecules = Number of moles of oxygen gas * Avogadro's number
= 0.125 moles * 6.022 x 10^23 molecules per mole
≈ 7.5275 x 10^22 molecules
Therefore, there are approximately 7.5275 x 10^22 molecules in 4 grams of oxygen gas.