When electrons flow steadily in one direction, the current is:

A mole of hydrogen atoms has 6.02 x 10^23 atoms. It occupies 22.414 L. How many hydrogen atoms are in 50.00 mL?

Greeley [361]

Answer:

This is a simple case of ratios. (1 mol)/(22.4 L)=(n mol)/(.025 L) Then we cross multiply and we get 22.4n=.025 We divide each side by 22.4 to find n=.001116 mol Then to convert the moles to atoms we multiply, and cross-cancel the units (.001116 mol)/1 xx (6.02 xx 10^23 atms)/(1 mol) and we have 6.72 xx 10^20 atoms. I've found the trick of cross-cancelling units to be a very effective mnemonic, it always makes sure you carry out the correct calculation to find the desired units.

Explanation:

3 0

3 years ago

A piece of magnesium ribbon reacts with oxygen to form magnesium oxide, mgo. what is the percent composition of the compound? qu

Wittaler [7]

The Percent composition of MgO is 60.304 % and 39.696 % respectively.

<h3>What percentage of the given chemical is there?</h3>

Mg + 1/2O₂ -------> MgO

We now want to know the percent composition of MgO in light of this reaction. Since the original reactants' and the product's mass are not provided, we can use the component's atomic weights to solve this problem.

Let's compute the molar mass of MgO since Mg has a molecular weight of 24.305 g/mol and O has a molecular weight of 15.999 g/mol:

molar mass of $MgO= 24.305 + 15.999 = 40.304 \frac{g}{mol}$