If 25 mL of a HCl solution of unknown concentration was neutralized with 10 mL of a 0.30 M NaOH solution, what was the original
1 answer:
Answer:
0.12 M
Explanation:
Step 1: Write the balanced equation
NaOH + HCl ⇒ NaCl + H₂O
Step 2: Calculate the reacting moles of NaOH
10 mL of a 0.30 M NaOH solution react.
Step 3: Calculate the reacting moles of HCl
The molar ratio of NaOH to HCl is 1:1. The reacting moles of HCl are 1/1 × 3.0 × 10⁻³ mol = 3.0 × 10⁻³ mol.
Step 4: Calculate the concentration of HCl
3.0 × 10⁻³ mol of HCl are in 25 mL of solution.
You might be interested in
Answer:
Of the following equilibria, only one will shift to the right in response to a decrease in volume.
On decreasing the volume the equilibrium will shift in right direction due to less number of gaseous moles on product side.
Explanation:
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.
This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
Decrease the volume
If the volume of the container is decreased , the pressure will increase according to Boyle's Law. Now, according to the Le-Chatlier's principle, the equilibrium will shift in the direction where decrease in pressure is taking place. So, the equilibrium will shift in the direction number of gaseous moles are less.
On decreasing the volume the equilibrium will shift in right direction due to less number of gaseous moles on product side.
On decreasing the volume the equilibrium will shift in left direction due to less number of gaseous moles on reactant side.
On decreasing the volume the equilibrium will shift in left direction due to less number of gaseous moles on reactant side.
On decreasing the volume the equilibrium will shift in no direction due to same number of gaseous moles on both sides.
On decreasing the volume the equilibrium will shift in no direction due to same number of gaseous moles on both sides.
Answer: 2.4 M
Explanation:
According to the neutralization law,
where,
= molarity of
solution = 3.5 M
= volume of
solution = 34.3 ml
= molarity of
solution = ?
= volume of
solution = 50 ml
= valency of
= 1
= valency of
= 1
Therefore, the concentration of NaOH solution is 2.4 M.
Answer:
The percentage (by mass) of KBr in the original mixture was 33.1%.
Explanation:
The mixture of KCl and KBr has a mass of 3.595g, thus the sum of the moles of KCl (<em>x</em>) multiplied by it molar mass (74.5g/mol) and the moles of KBr (<em>y</em>) multiplied by it molar mass (119g/mol) is the total mass of the mixture:
Also, after the conversion of KBr into KCl, the total mass of 3.129 g is only from KCl moles, hence
But the 0.042 moles came from the originals KCl and KBr moles, thus
Now it is possible to propose a system of equations:
Solving the system of equations,
0.010 moles of KBr multiplied it molar mass is
Therefore, the percentage (by mass) of KBr in the original mixture was:
%