when 12.76mL of HCl of unknown concentration (but less than the base) are reacted with 15mL of 3.254M NaOH, 1.68kJ of heat are released. What is the molarity of the HCl solution?
Have you been working with heats of reaction? Do you know the kJ heat released on neutralization of HCl and NaOH? I don't know that number.
neutralization is -55.84kJ/mol
I am disappointed in western students....the day before your lab as well
my lab is actually not until next week
and i go to brock
To find the molarity of the HCl (hydrochloric acid) solution, we need to use the concept of stoichiometry and the heat of reaction. Here's how we can approach this problem step by step:
Step 1: Write the balanced chemical equation for the reaction between HCl and NaOH:
HCl + NaOH → NaCl + H2O
Step 2: Identify the relevant information given in the question:
- Volume of HCl solution: 12.76 mL
- Volume of NaOH solution: 15 mL
- Concentration of NaOH solution: 3.254 M
- Heat released during the reaction: 1.68 kJ
Step 3: Use the volume and concentration information to calculate the number of moles of NaOH:
moles of NaOH = volume (L) × concentration (M)
moles of NaOH = 0.015 L × 3.254 M = 0.04881 moles
Step 4: Use the balanced equation to determine the mole ratio between NaOH and HCl. From the equation, we know that 1 mole of NaOH reacts with 1 mole of HCl.
Step 5: Since the mole ratio is 1:1, the number of moles of HCl is also 0.04881 moles.
Step 6: Now, we can calculate the molarity (concentration) of the HCl solution using the given volume:
molarity (M) = moles of solute / volume of solution (L)
molarity of HCl = 0.04881 moles / 0.01276 L = 3.825 M
Therefore, the molarity of the HCl solution is approximately 3.825 M.