Chemical reactions that absorb energy are said to be ________

What is it when a cup of ice turns to water

timurjin [86]

I don't really know what your question is asking so I am just going to list a few facts that I think might be what you are asking.

Ice turning into water is a physical change. The ice is undergoing the process of melting which does not change it chemically (ice and water are chemically identical in the sense that they are both composed of H₂O molecules) and the only difference between water and ice is that water molecules have a higher average amount of energy than the ice molecules do. When a substance melts, the molecules within the substance gain energy (in the form of heat) which allows them to break the intermolecular forces keeping them together. Since the melting of ice requires energy, the process is endothermic which means that the ice had to get energy from its surroundings and that water has more energy than ice does as a result of the process (ΔH is positive).

I hope that helps. Let me know in the comments if anything is unclear or if I did not answer your question.

5 0

3 years ago

Read 2 more answers

If evaporation occurs what will change 0.70 molar solution of CuSO4

faust18 [17]

Answer:

A. Molarity will increase .

Explanation:

Molarity = moles of solute per litre of solution

= moles of solute / volume of solution

If evaporation occurs , volume of solution decreases and moles of solute remains constant . Hence denominator decreases and numerator remains constant .

Hence the molarity increases .

3 0

3 years ago

A sample was prepared by mixing 18. ml of 3.00 x 10^-3 m crystal violet (cv) with 2.00 ml of 0.250 m naoh. calculate the resulti

Aleks [24]

Answer : The resulting concentrations of CV and NaOH are 0.0027 M and 0.025 M respectively.

Explanation :

Step 1 : Find moles of crystal violet and NaOH.

The molarity formula is

$Molarity = \frac{mol}{L}$

Molarity of crystal violet = $3.00 \times 10^{-3} = \frac{mol (CrystalViolet)}{L}$

The volume of crystal violet solution is 18 mL which is 0.018 L.

Moles of crystal violet = $3.00 \times 10^{-3} \times 0.018 = 5.4 \times 10^{-5}$

Moles of crystal violet = 5.4 x 10⁻⁵

Moles of NaOH = $Molarity \times L = 0.250 \times 0.00200 = 5.00 \times 10^{-4}$

Moles of NaOH = 5.00 x 10⁻⁴

Step 2 : Find total volume of the solution

The total volume of the solution after mixing NaOH and crystal violet is

0.018 L + 0.00200 = 0.020 L

Step 3 : Use molarity formula to find final concentrations

Molarity of crystal violet = $\frac{mol(CrystalViolet)}{Total Volume(L) } = \frac{5.4 \times 10^{-5}}{0.020} = 2.7 \times 10^{-3}$

Final concentration of CV = 0.0027 M

Molarity of NaOH= $\frac{mol(NaOH)}{Total Volume(L) } = \frac{5.00 \times 10^{-4}}{0.020} = 0.025 \times 10^{-3}$

NaOH is a strong base and dissociates completely as follows.

$NaOH (aq) \rightarrow Na^{+} (aq) + OH^{-} (aq)$

The mole ratio of NaOH and OH⁻ is 1:1 . Therefore the concentration of OH⁻ is same as that of NaOH.

Concentration of OH⁻ = 0.025 M

8 0

3 years ago

8. 00 g of ethane gas, c2h6, is burned in oxygen. What volume of carbon dioxide gas is produced at 1. 00 atm and 25. 0°c?.

Sonbull [250]

Answer:

Explanation:1 g CH

4

,C

2

H

6

C

3

H

8

C

4

H

10

T = 350 K, P = 1 atm

PV=nRT=

M

w×R×T

1×V=

58

1

×0.0821×350

V=0.495 L

V=495cm

3

8 0

1 year ago

Electric service has accumulated on an object is referred to as

lara31 [8.8K]

Answer:

Static Electricity! :)

Explanation:

3 0

3 years ago

Chemical reactions that absorb energy are said to be _________.