Molality of the solution is defined as the number of moles of a substance dissolved divided by the mass of the solvent:
Molality = number of moles / solvent mass
From the concentration of 39% (by mass) of HCl in water, we construct the following reasoning:
in 100 g solution we have 39 g hydrochloric acid (HCl)
number of moles = mass / molecular weight
number of moles of HCl = 39 / 36.5 = 1.07 moles
solvent (water) mass = solution mass - hydrochloric acid mass
solvent (water) mass = 100 - 39 = 61 g
Now we can determine the molality:
molality = 1.07 moles / 61 g = 0.018
Answer:
<h2>The answer is 35 mL</h2>
Explanation:
Density of a substance can be found by using the formula

From the question we are finding the amount of space the gas will occupy that's the volume of the gas
Making volume the subject we have

From the question
mass = 23.8 g/mL
Density = 0.68 g/mL
Substitute the values into the above formula and solve
That's

We have the final answer as
<h3>35 mL</h3>
Hope this helps you
Answer:
A non example of a galaxy is a star
A fossilized fish could be used to identify the date of of the rock layer.
Answer:
In 4 years the carbon monoxide level reach 7.8 parts per million.
Explanation:
The average daily level of carbon monoxide in the air is given by :
parts per million..[1]
The population of the region after t years is modeled by the formula :
...[2]
If level of carbon monoxide level reach 7.8 parts per million in t years.
Using [1] to calculate value of x.
c(x)= 7.8 parts per million
c(x) = 0.5x + 2 parts per million
7.8 parts per million = (0.5x + 2 ) parts per million
Solving for x , we get ;
x = 11.6
Using [2] to calculate value of t.:
x(t) = 11.6

Solving for 't' we get ;
t = 4 years
In 4 years the carbon monoxide level reach 7.8 parts per million.