Concentration is the number of moles of solute in a fixed volume of solution
Concentration(c) = number of moles of solute(n) / volume of solution (v)
25.0 mL of water is added to 125 mL of a 0.150 M LiOH solution and solution becomes more diluted.
original solution molarity - 0.150 M
number of moles of LiOH in 1 L - 0.150 mol
number of LiOH moles in 0.125 L - 0.150 mol/ L x 0.125 L = 0.01875 mol
when 25.0 mL is added the number of moles of LiOH will remain constant but volume of the solution increases
new volume - 125 mL + 25 mL = 150 mL
therefore new molarity is
c = 0.01875 mol / 0.150 L = 0.125 M
answer is 0.125 M
Answer:
1.22 mL
Explanation:
Let's consider the following balanced reaction.
2 AgNO₃ + BaCl₂ ⇄ Ba(NO₃)₂ + 2 AgCl
The molar mass of silver chloride is 143.32 g/mol. The moles corresponding to 0.525 g are:
0.525 g × (1 mol/143.32 g) = 3.66 × 10⁻³ mol
The molar ratio of AgCl to BaCl₂ is 2:1. The moles of BaCl₂ are 1/2 × 3.66 × 10⁻³ mol = 1.83 × 10⁻³ mol.
The volume of 1.50 M barium chloride containing 1.83 × 10⁻³ moles is:
1.83 × 10⁻³ mol × (1 L/1.50 mol) = 1.22 × 10⁻³ L = 1.22 mL
Check the attached file for the answer.
Answer:
ΔG°rxn = -72.9 kJ
Explanation:
Let's consider the following reaction.
HCN(g) + 2 H₂(g) → CH₃NH₂(g)
We can calculate the standard Gibbs free energy of the reaction (ΔG°rxn) using the following expression:
ΔG°rxn = ΔH° - T.ΔS°
where,
ΔH° is the standard enthalpy of the reaction
T is the absolute temperature
ΔS° is the standard entropy of the reaction
ΔG°rxn = -158.0 KJ - 387 K × (-219.9 × 10⁻³ J/K)
ΔG°rxn = -72.9 kJ
Answer:
Explanation:
q = (mass) (temp change) (specific heat)
q = (10000 g) (40 °C) (0.385 J/g⋅°C) = 154000 J = 154 kJ
154 kJ / 2220 kJ/mol = 0.069369369 mol
0.069369369 mol times 44.0962 g/mol = 3.06 g (to three sig figs)
answer choice 4
