I need the answer so much

Which of the graphs below might represent a mixture of pure water and ice exposed to a room temperature of 3°C?

Y_Kistochka [10]

Answer:

C. Graph C

Explanation:

We have a mixture of water and ice.

At 0 °C they are at equilibrium.

water-to-ice rate = ice-to-water rate

Next, we lower the temperature to -3 °C — just slightly below freezing.

The water will slowly turn to ice.

The water-to-ice rate will be slightly faster than the ice-to-water rate.

The purple bar will be slightly higher than the blue bar.

Graph C best represents the relative rates

A. is wrong. The ice-to-water rate is faster, so the water is melting. The temperature is slightly above freezing (say, 3 °C).

B. is wrong. The two rates are equal, so the temperature is 0 °C.

D. is wrong. The water-to-ice rate (freezing) is much greater than the ice-to-water rate, so the temperature is well below freezing( say, -10 °C).

6 0

4 years ago

A cupcake recipe designed to produce 18 cupcakes calls for 260 grams of

Vedmedyk [2.9K]

Answer:

317.7778 g

Explanation:

Given data:

Flour required for 18 cup cakes = 260 g

Flour required for 22 cup cakes = ?

Solution:

We will calculate the flour required for 1 cup cake.

260 g /18 = 14.4444 g

Fluor required for 22 cupcakes,

22× 14.4444 g = 317.7778 g

In short,

22 cupcake/18 cup cake×260 g = 317.7778 g

8 0

3 years ago

What is happening to the temperature of the substance BEFORE AND AFTER the phase changes?

Neporo4naja [7]

First off, you must realize that the phase changes are marked by the points B and D on the graph. They are level because all of the energy (or heat) being added is being consumed by the physical process. So The temperature is increasing before the phase change, and after the phase change. The moments before and after are represented by points A, C, and E.

5 0

3 years ago

A chemist wants to extract a solute from 100 mL of water using only 300 mL of ether. The partition coefficient between ether and

devlian [24]

Answer:

a. X = 0,909

b. X = 0,965

c X = 0,997

Explanation:

The partition coefficient (k) is defined as:

k = Solute in ether / solute in water

a. $3,34 = \frac{\frac{X}{300mL} }{\frac{1-X}{100mL} }$

Where X is the fraction of solute extracted

3,34 = X / 3-3X

10,02-10,02X = X

10,02 = 11,02X

X = 0,909

b. First extraction:

$3,34 = \frac{\frac{X}{100mL} }{\frac{1-X}{100mL} }$

3,34 = X / 1-X

3,34 - 3,34X = X

3,34 = 4,34X

X = 0,770

That means solute in water will be: 1-0,770 = 0,23

Second extraction:

The second extraction will extract the same fraction of solute, as now you have 0,230 of solute in water you will extract:

0,230×0,770 = 0,177

Third extraction:

In the same way, the third extraction will extract:

(0,230-0,177)×0,770 = 0,018

Fraction in water×Fraction extracted

That means total solute extracted is:

0,770 + 0,177 + 0,018 = 0,965

c. Extracting with 50mL of ether:

First extraction

$3,34 = \frac{\frac{X}{50mL} }{\frac{1-X}{100mL} }$

3,34 = 2X / 1-X

3,34 - 3,34X = 2X

3,34 = 5,34X

X = 0,625

Second extraction:

(1-0,625)×0,625= 0,234

Third Extraction:

(1-0,625-0,234)×0,625= 0,088

Fourth extraction:

(1-0,625-0,234-0,088)×0,625= 0,033

Fifth extraction:

(1-0,625-0,234-0,088-0,033)×0,625= 0,013

Sixth extraction:

(1-0,625-0,234-0,088-0,033-0,013)×0,625= 0,004

Total extractions gives:

0,625+0,234+0,088+0,033+0,013+0,004 = 0,997

I hope it helps!

8 0

4 years ago

What volume (in mL) of 0.0887 M MgF2 solution is needed to make 275.0 mL of 0.0224 M MgF2 solution?

Bond [772]

Answer : 69.44 mL

Explanation : Here we can use the formula as $M_{1} V_{1} =M _{2}V_{2}$

Where we have the value of $M_{1}$ = 0.0887 M
$M_{2}$ = 0.0224 M and
$V_{2}$ = 275 mL

So, substituting the above values in the given equation we get,

0.0887 X x = 275 X 0.0224

Therefore, x = 69.44 mL

So it will require 69.44 mL.

4 0

3 years ago