Question

When do I know what the tolerance of my capacitor might be? The stamped value of my capacitor is 2.50x10^4F

Answer 1

In addition to the capacitance value (and possibly the working voltage or breakdown voltage) the capacitor may be marked by its tolerance.
There are several tolerance marking systems used; two of the most common are shown here. The first is used with small ceramic capacitors, and appears as a single letter.

Ceramic Capacitor Tolerance Markings

Code	Tolerance		Code	Tolerance
B	± 0.1 pF		J	± 5%
C	± 0.25 pF		K	± 10%
D	± 0.5 pF		M	± 20%
F	± 1%		Z	+ 80%, -20%
G	± 2%

The second is used for a variety of capacitor types, and is indicated by a unique assortment of lettrs and numbers, which represent the low and high temperature requirements (the lower and upper acceptable temperature range of operating the capacitor), and its tolerance within this temperature range.

EIA Capacitor Tolerance Markings

1st Letter Symbol	Low Temp. Requirement		Number Symbol	High Temp. Requirement		2nd Letter Symbol	Max. Capacitance Change Over Temperature Rating
Z	+10° C		2	+45° C		A	±1.0%
Y	-30° C		4	+65° C		B	±1.5%
X	-55° C		5	+85° C		C	±2.2%
			6	+105° C		D	±3.3%
			7	+125° C		E	±4.7%
						F	±7.5%
						P	±10.0%
						R	±15.0%
						S	±22.0%
						T	±22% ~ 33%
						U	±22% ~ 56%
						V	±22% ~ 82%

Example: Y5P = ± 10% variation of temperature over range of -30° C to +85° C.

Note: In your case just by knowing the stamped value of my capacitor is 2.50x10^4F you could not be able to know capatitor tolerence.