A sample of solid ammonium sulfide (NH4)2S is placed in a closed bulb which is then filled with 0.0150 mol of inert HE gas. The pressure of the He at 25 degrees Celsius is 145 mmHg. The bulb is then heated to 325 degrees Celsius and all of the (NH4)2S decomposes to form gaseous NH3 and H2S, with a resulting total gas pressure int eh bulb of 875 mmHg. What ist he partial rpessure of the NH3 gas int eh bulb at 325 degrees Celsius?
a. 145 mmHg
b. 195 mmHg
c. 389 mmHg
d. 435 mmHg
e. 875 mmHg