Answer:
0.0835 M
Explanation:
Step 1: Write the balanced equation
NaOH + HCl ⇒ NaCl + H₂O
Step 2: Calculate the reacting moles of HCl
0.0250 L of 0.105 M HCl react.
0.0250 L × 0.105 mol/L = 2.63 × 10⁻³ mol
Step 3: Calculate the reacting moles of NaOH
The molar ratio of NaOH to HCl is 1:1. The reacting moles of NaOH are 1/1 × 2.63 × 10⁻³ mol = 2.63 × 10⁻³ mol.
Step 4: Calculate the molarity of NaOH
2.63 × 10⁻³ moles of NaOH are in 0.0315 L of solution.
M = 2.63 × 10⁻³ mol / 0.0315 L = 0.0835 M
Answer:
2.5 g of platinum
Explanation:
Recall that a catalyst is a specie added to a reaction system to increase the rate of reaction. A catalyst does not participate in the chemical reaction hence it remains unchanged at the end of the chemical reaction. A catalyst merely provides an alternative reaction pathway by lowering the activation energy of the reaction system. Hence a catalysed reaction usually proceeds faster with less energy requirement than the uncatalysed reaction.
Since the catalyst does not participate in the reactions and remains unchanged at the end of the reaction, the mass of platinum will remain the same (2.5g). The mass can only change if a specie participates in the chemical reaction. Hence the answer.
P = 600 mmHg
V = 2.2 L
T = 85°C
R = 0.08206 L atm / mol K
n = ?
I would start by converting the P from mmHg to atm, since our gas constant R uses atm.
600 mmHg • 1 atm / 760 mmHg = 0.789 atm = P
Then I would convert T from Celsius to Kelvin, since our gas constant R uses Kelvin.
85 + 273 = 358 K
Now you can solve PV = nRT for n, giving you:
n = PV/RT
n = (0.789 atm)(2.2 L) / (0.08206 L atm / mol K)(358 K) = 0.059 moles of gas
<span>In the study of science, it is also very important to know that all solids are not the same, all liquids are not the same, and all gases are never the same. </span>
