4) A 4.00 L balloon is filled with 0.297 moles of helium gas with a pressure of 0.910 atm. Calculate the temperature, in Kelvin, of the gas. (KEEP 3 SIG

FIGS; DO NOT TYPE ANY UNITS)*

149

Explanation:

Using the ideal gas equation; PV = nRT

P= Pressure = 0.910 atm,     T= Temperature = ?

V= Volume = 4.0L                  R = Gas constant = 0.08206 L.atm/mol/K

n = number of moles = 0.297

Making 'T' the subject of the formular, we have;

T = P V/ n R   =  0.910  x 4  /  0.297 x 0.08206

                       =  149

You would use the equation y = A(1+r)^t 

A = Original amount = 200
r = interest rate = 0.042 (when converted from percent to decimal)
t = time = x 

Plug them in and you get the model: y = 200(1+0.042)^x 

or just simplify the parentheses to (1.042)