Aprotein subunit from an enzyme is part of a research study and needs to be characterized. a total of 0.155 g of this subunit was dissolved in enough water to produce 2.00 ml of solution. at 28 ∘c the osmotic pressure produced by the solution was 0.138 atm. what is the molar mass of the protein?

Answer : The molar mass of protein is,

Explanation :

Formula used :

where,

= osmotic pressure  = 0.138 atm

C = concentration

R = solution constant  = 0.0821 L.atm/mol.K

T = temperature  =

w = mass of protein subunit = 0.155 g

M = molar mass of protein subunit = ?

V = volume of solution  = 2.00 mL

Now put all the given values in the above formula, we get:

Therefore, the molar mass of protein is,

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

sorry i was late, but i don't know what assignment your talking about, i'm in flvs as well, im in earth space science. but u are behind pace bc every class should be in the 3's or 4'