Answer is: molarity of hydrofluoric solution is 0.09 M.
Chemical reaction: HF(aq) + KOH(aq) → KF(aq) + H₂O(l).
V(HF) = 30.0 mL.
c(KOH) = 0.122 M.
V(KOH) = 22.15 mL:
c(HF) = ?.
From chemical reaction: n(HF) : n(KOH) = 1 : 1.
n(HF) = n(KOH).
c(HF) · V(HF) = c(KOH) · V(KOH).
c(HF) = c(KOH) · V(KOH) ÷ V(HF).
c(HF) = 0.122 M · 22.15 mL ÷ 30 mL:
c(HF) = 0.09 M.
The answer is the option<span> 3.) Fixing a wineglass requires a large decrease in entropy.
Entropy is a termodynamical variable and it is defined as the degree of disorder of the system.
As per the second law of thermodynamics the spontaneous changes only occur when the entropy increases.
</span>Fixing the broken glasses by itself meant to decrease the entropy spontaneusly which violate the principle or second law of thermodynamics. So, it is not possible.
Answer:
Q = 30355.2 J
Explanation:
Given data:
Mass of ice = 120 g
Initial temperature = -5°C
Final temperature = 115°C
Energy required = ?
Solution:
Specific heat capacity of ice is = 2.108 j/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Q = m.c. ΔT
ΔT = T2 -T1
ΔT = 115 - (-5°C)
ΔT = 120 °C
Q = 120 g × 2.108 j/g.°C × 120 °C
Q = 30355.2 J
Answer:
4.25*10^18
Explanation:
1 mole =6.023*10^23 particles
so 7.07*10^-6 mole=6.023*10^23*7.07*10^-6 particles=4.25*10^18 particles
