We add a 1.20-g sample of dry ice to a 755-ml flask containing nitrogen gas at a temperature of 25.0 c and a pressure of 725mmhg. the dry ice sublimes (converts from solid to gas) and the mixture returns to 25.0 c. what is the total pressure in the flask?

Total pressure is 1396 mmHg

Explanation:

By:

PV/RT = n

It is possible to obtain the initial moles of nitrogen gas, where:

P is pressure (725 mmHg = 0,954 atm)

V is volume (0,755L)

R is gas constant (0,082atmL/molK)

T is temperature (25,0°C = 298,15 K)

Replacing:

n = 0,02946 moles of nitrogen gas.

The moles of dry ice (CO₂; molar mass= 44,01 g/mol) are:

1,20 g × (1mol/44,01g) = 0,02727 moles of dry ice.

When dry ice sublimes, total moles are:

0,02727 + 0,02946 = 0,05673 moles

With the temperature (25,0°C = 298,15 K) and volume (0,755L) it is possible to obtain total pressure, thus:

P = nRT/V

Replacing:

P = 1,837 atm × (760 mmHg/1atm) = 1396 mmHg

I hope it helps!

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

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