Find the mass of water (H2O) needed to react with 150 grams of potassium (K)
2K(s) + 2 H2O (g)-2KOH +H2(g)
How do I get the number of moles in H2O?
Desperate to understand this.
I got K= 150g./39.0983=3.84 mols of K.
Then would it be 3.84(2mols H2O/7.68)
How do I get the proper equation to figure out what 2 moles of H2O would be.
If you can walk me through this problem I will understand it and be able to continue with my work.
Is this correct?
3.84 mol(2 H2O/7.68 ????
To find the mass of water (H2O) needed to react with 150 grams of potassium (K), you first need to determine the balanced chemical equation for the reaction. From the given equation:
2K(s) + 2H2O(g) -> 2KOH + H2(g)
The coefficients in the balanced equation indicate the ratio of moles of each substance involved in the reaction.
To calculate the moles of K, you correctly divided the given mass of K (150 g) by its molar mass (39.0983 g/mol), giving you 3.84 mol of K.
To find the moles of H2O that react with 3.84 mol of K, you can use the stoichiometric ratio between K and H2O, which is 2:2. This means that for every 2 moles of K, 2 moles of H2O are consumed in the reaction.
So, you can set up the following proportion:
3.84 mol K / 2 mol K = x mol H2O / 2 mol H2O
Simplifying the expression, you will get:
1.92 = x mol H2O / 2 mol H2O
To find the value of x (the number of moles of H2O), you can cross-multiply and solve for x:
x = 1.92 mol H2O
Now, to calculate the mass of H2O, you can multiply the number of moles (1.92 mol) by its molar mass (18.0153 g/mol) to get:
mass of H2O = 1.92 mol * 18.0153 g/mol = 34.65 g
Therefore, the mass of water (H2O) needed to react with 150 grams of potassium (K) is 34.65 grams.