Chemistry question

Question

45g of Hydrobromic acid is neutralized with 100g of sodium hydroxide.

a) write the balances reaction.

b) determine the amount of water that will be produced.

c) would acid or base be left over after the reaction is complete. Explain.

Answer 1

a). HBr(aq) + NaOH(aq) ==> NaBr(aq) + H2O(l) .. balanced equation

b). Find the limiting reactant: one way is to divided moles of each reactant by the corresponding coefficient in the balanced equation. Whichever value is less will indicate the limiting reactant.

HBr: 45 g x 1 mol / 80.9 g = 0.556 mols (÷1->0.556)

NaOH: 100 g x 1 mol / 40 g = 2.5 mols (÷1->2.5)

Clearly, HBr is limiting since 0.556 is less than 2.5. The moles of HBr (0.556) will dictate moles H2O

moles of H2O formed = 0.556 mol HBr x 1 mol H2O / mol HBr = 0.556 mols H2O

mass of H2O formed = 0.556 mols H2O x 18 g / mol = 10.0 g H2O

c). Since HBr is the limiting reactant, base (NaOH) will be left over after the reaction is complete. This is explained by the fact that HBr and NaOH react in a 1:1 mole ratio, but since there are many more moles of NaOH (2.5 mols) than there are HBr (0.556), NaOH will be left over after the reaction.

Answer 2

a) The balanced reaction between hydrobromic acid (HBr) and sodium hydroxide (NaOH) can be written as follows:

HBr + NaOH → NaBr + H2O

b) To determine the amount of water produced, we need to compare the stoichiometric ratio of hydrobromic acid and water in the balanced equation. The molar ratio between HBr and H2O is 1:1, which means that for every 1 mole of HBr reacted, 1 mole of H2O is produced.

First, we need to convert the given masses of HBr and NaOH to moles using their molar masses:

Molar mass of HBr = 1 g/mol + 79.9 g/mol = 80.9 g/mol

Molar mass of NaOH = 23 g/mol + 16 g/mol + 1 g/mol = 40 g/mol

Moles of HBr = 45 g / 80.9 g/mol ≈ 0.556 mol

Moles of NaOH = 100 g / 40 g/mol = 2.5 mol

Since the balanced equation shows a 1:1 molar ratio between HBr and H2O, the amount of water produced will be 0.556 moles.

c) In this reaction, the stoichiometric ratio between HBr and NaOH is 1:1. This means that the reaction will completely consume the available 0.556 moles of HBr, leaving no excess acid۔