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3 years ago

Will Upvote!

Chemistry

2 answers:

Greeley [361]3 years ago

4 0

I would think energy has been transferred <span />

Degger [83]3 years ago

3 0

Answer:

B. Energy was transferred

Explanation:

All chemical and biochemical reactions release or absorb energy from the environment in some way. Every process of heat transfer between bodies, substances and the enviroment is also considered a process of energy transfer.

The processes that release heat are called exothermic and give us a feeling of warmth. This is the case, for example, with combustion.

On the other hand, the sensation of cold we feel when leaving a bath, or when we take an ice cube, is associated with endothermic processes. Such processes, like evaporation and fusion of water, for example, absorb heat from the environment and this can also be perceived by our body.

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What is weathering? Please explain in your own words.

Annette [7]

To slowly erode and crumble.

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4 years ago

What is the percentage of sodium presents in sodium hydrogen carbonate NaHCO3

STatiana [176]

Answer:-

27.38%

Explanation:-

Molecular weight of sodium hydrogen carbonate NaHCO3

= 23 x 1 + 1 x 1 + 12 x 1 + 16 x 3

= 84 gram

Total sodium Na present in NaHCO3 = 23 x 1 = 23 gram

Percentage of sodium present=

Total sodium x 100/ (Total molecular weight)

= 23 x 100 / 84

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3 years ago

A stock phenolphthalein solution was prepared by dissolving 0.050 g in a total volume of 100.0 ml. You place one drop (0.050 ml)

devlian [24]

Answer:

the value of molar absorptivity is 229000 $M^{-1} cm^{-1}$

Explanation:

given data

phenol phthalein solution = 0.050 g

total volume = 100.0 ml

dilute = 100.0 ml

diluted sample = 0.18

solution

we get here concentration that is express as

concentration = ( mass of solute × 1000 ) ÷ ( molar mass of solute × volume of solution ) .............1

put here value

concentration = $\frac{0.050\times 1000}{318.32\times 100}$

concentration = 0.00157 M

and here dillution equation is express as

c1 × v1 = c2 × v2 .................2

here c1 and c2 is initial and final concentration

and v1 and v2 is initial and final volume

put here value

0.001571 × 0.050 = c2 × 100

c2 = 7.855 × $10^{-7}$ M

and

now we get molar by absorbance equation that is

A = E × C × l ................3

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put here value

0.18 = E × 7.855 × $10^{-7}$ × 1

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3 years ago

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lapo4ka [179]

B. 6.02 x 10^23 atoms

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3 years ago

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Identify the type of reaction:

miskamm [114]

It’s #2 because I saw on edigunity 2020

7 0

3 years ago