I'm taking the same quiz. The answer is column
HF - The liquid state of this compound will exhibit hydrogen bonding due to the large electronegativity of H and F.
CF4 - The liquid state of this compound will exhibit van der Waals forces.
H2S - The liquid state of this compound will exhibit dipole-dipole or electrostatic attraction forces.
Answer:
The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.
Explanation:
The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:
n = 1.375x10⁻⁵ mol
The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):
1.375x10⁻⁵ mol _________ 19.9 units
x _________ 25.2 units
x = 1.741x10⁻⁵mol
Finally, we can calculate the Cu²⁺ concentration :
C = 1.741x10⁻⁵mol / 0.025 L
C = 6.964x10⁻⁴ M
Molar mass:
CH₄ = 12 + 1 x 4 = 16.0 g/mol
CO₂ = 12 + 16 x 2 = 44.0 g/mol
Balanced <span>equation :
</span>
<span>CH</span>₄<span> + 2 O</span>₂<span> = CO</span>₂<span> + 2 H</span>₂<span>O
</span>
16.0 g CH₄ --------------- 44.0 g CO₂
(mass of CH₄) ----------- 46.4 g CO₂
mass of CH₄ = 46.4 x 16.0 / 44.0
mass of CH₄ = 742.4 / 44.0
= 16.87 g CH₄
hope this helps!