<span>Platinum is solid at room temperature. SInce the catalyst is solid while the medium involves gases, this catalyst is characterized as heterogenous. Because they are different states of matter, they can be easily separated through physical means. So, the answer is B.</span>
Explanation:
A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Every person has two copies of each gene, one inherited from each parent. Most genes are the same in all people, but a small number of genes (less than 1 percent of the total) are slightly different between people. These small differences contribute to each person’s unique physical features.
Find the number of moles of sodium you have:
<span>n = m/M where m is your 20g of sodium and M is 22.99 g/mol. </span>
<span>Look at the stoichiometry of the equation - it's 2:2 when you are producing NaOH. So if you took 1 mole of Na, it'd produce 1 mole of NaOH (as the ratio is equal). </span>
<span>That means that your moles of sodium is equal to the moles of NaOH produced. Use the molar mass of NaOH - which is 39.998 g/mol along with your calculated number of moles to get the mass (the formula rearranges to m = nM). </span>
<span>This figure is the theoretical yield - what you would get if every last mole of sodium was converted into NaOH. </span>
<span>What you get in practice is the experminetal yield, and the percentage yield is the experimental yield divided by the theoretical yield - and then multiplied by 100%.</span>