Answer:
The answer to your question is 33.4 ml
Explanation:
Data
volume 1 = V1 = 42 ml
temperature 1 = T1 = 20°C
temperature 2 = T2 = -60°C
Volume 2 = V2 = x
Process
1.- Convert celsius to kelvin
T1 = 20 + 273 = 293°K
T2 = -60 + 273 = 233°K
2.- Use the Charles' law to solve this problem

Solve for V2
V2 = 
3.- Substitution
V2 = 
4.- Simplification
V2 = 
5.- Result
V2 = 33.4ml
Answer:
K⁺ (aq) + F⁻ (aq) + H⁺ (aq) + Cl⁻ (aq) → KCl (aq) + H⁺ (aq) + F⁻ (aq)
Explanation:
KF (aq) + HCl (aq) → KCl (aq) + HF (aq)
KF (aq) → K⁺ (aq) + F⁻ (aq)
HCl (aq) → H⁺ (aq) + Cl⁻ (aq)
KCl (aq) → K⁺ (aq) + Cl⁻ (aq)
HF (aq) → H⁺ (aq) + F⁻ (aq)
NH3 + H2O -> NH4+ + OH- is the answer I think I just did this in class today
Is constant (matter that has a composition that is the same everywhere)