Which image shows an example of the strong nuclear force in action?

A 19.12 g mixture of Ca(NO3)2 and KCl is dissolved in 149 g of water. The freezing point of the solution was measured as −5.77 ∘

hichkok12 [17]

Answer:

The mass percentage of calcium nitrate is 31.23%.

Explanation:

Let the the mass of calcium nitrate be x and mass of potassium chloride be y.

Total mass of mixture = 19.12 g

x + y = 19.12 g..(1)

Mass of solvent = 149 g = 0.149 kg

Freezing point of the solution, $T_f$ = -5.77 °C

Molal freezing constant of water = 1.86 °C/m =1.86 °C/(mol/kg)

The van't Hoff factor contribution by calcium nitrate is 3 and by potassium chloride is 2.So:

i = 3

i' = 2

Freezing point of water = T = 0°C

$\Delta T_f=T-T_f=0^oC-(-5.77^oC)=5.77^oC$

$\Delta T_f=i\times K_f\times m$

$Molality=m(mol/kg)=\frac{\text{Moles of solute}}{\text{mass of solvent in kg}}$

$5.77^oC=1.86 ^oC/(mol/kg)\times (\frac{ i\times x}{164 g/mol\times 0.149 kg}+\frac{i'\times y}{74.5 g/mol0.149 kg})$

On solving we get:

$\frac{3x}{164 g/mol}+\frac{2x}{74.5 g/mol}=0.4622 mol$ ....(2)

Solving equation (1)(2) for x and y:

x =5.973 g

y = 13.147 g

Mass percent of $Ca(NO_3)_2$ in the mixture:

$\frac{x}{19.21 g}\times 100=\frac{5.973 g}{19.12 g}=31.23\%$

The mass percentage of calcium nitrate is 31.23%.

5 0

3 years ago

What is an athlete’s momentum if the athlete has a velocity of 7.5 m/s and has a mass of 70kg?

Bezzdna [24]

Answer:

525 kg.m/s

Explanation:

★ Momentum = Mass× Velocity

→ P = (7.5 × 70) kg.m/s

→ P = (75 × 7) kg.m/s

→ P = 525 kg.m/s

8 0

2 years ago

Every object that has mass attracts every other object with a gravitational force. It has been proven that the size of the gravi

Blababa [14]

Newton's law of universal gravitation

7 0

3 years ago

Read 2 more answers

A rock falls from rest off a cliff and hits the ground in 2 seconds. If there is no air resistance, determine the rock's velocit

mihalych1998 [28]

Answer:

19.6m/s

Explanation:

A Rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for certain period of time, for such motion following equation of motion can be used.

$v(t) = v_{0} +at$

here in our case $v_{0} =0$ because object starts off from rest and $a = g =9.8m/s^2$ is acceleration because of gravity ( Motion under gravity).

and of course t = 2 second.

Now by substituting all this information in equation of motion we get.

$v(2s) = 0+9.8m/s^2 *2s = 19.6m/s$

that would be the velocity of rock as it would hit the ground.

Note! We have assumed that there is no air resistance.

A rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for a certain period of time, for such motion following equation of motion can be used.

here in our case because object starts off from rest and is acceleration because of gravity ( Motion under gravity).

and of course t = 2 seconds.

Now by substituting all this information in equation of motion we get.

V = 19.6m/s

that would be the velocity of rock as it would hit the ground.

Note! We have assumed that there is no air resistance.

5 0

3 years ago

How do you relate and explain a planet's distance from the Sun to things like the time of their year & their average tempare

anzhelika [568]

What we call a "year" is the time a body takes to complete one orbital revolution
in its path around the sun. The way gravity works, the farther a planet is from the
sun, the slower it moves, and the longer it takes to complete that trip. So, farther
out from the sun means a longer "year".

Everybody knows that if you want to get more warmth, then you have to stand closer
to the fire, and it's the same with planets. The farther a planet is from the sun, the less
heat it gets from the sun, and in most cases, that means its average temperature is
lower. (The planet's average temperature is affected by other things besides its distance
from the sun, such as how much heat comes up from inside, and how much heat its
atmosphere traps.)

The farther a planet's rotation axis is tilted from being perpendicular to the plane
of its orbit, the more seasonal variation there can be in the temperature at any one
place on its surface. Of course, this is kind of irrelevant if the planet has no surface.

5 0

3 years ago