Answer:
2.1 atm
Explanation:
We are given the following variables to work with:
Initial pressure (P1): 2.5 atm
Initial temperature (T1): 320 K
Final temperature (T2): 273 K
Constant volume: 7.0 L
We are asked to find the final pressure (P2). Since volume is constant, we want to choose a gas law equation that relates initial pressure and temperature to final pressure and temperature. Gay-Lussac's law does this:

We can rearrange the law algebraically to solve for
.

Substitute your known variables and solve:

Answer:
+1.76 V
Explanation:
Ecell = Ecathode - Eanode
= -0.19 - (-1.95) = + 1.76 V
B is the answer or check it out
Explanation:
F = k.m1.m2/r²
m1 and m2: masses of objects
r: distance between the objects
k: a constant