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2 years ago

Which of the following processes are physical changes?

Chemistry

2 answers:

lubasha [3.4K]2 years ago

8 0

C) cutting a snowflake out paper
because someone has to physically cut the paper into a snowflake

Stolb23 [73]2 years ago

7 0

C) and d) are physical changes while b) is chemical

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Th e molar absorption coeffi cient of a substance dissolved in water is known to be 855 dm3 mol−1 cm−1 at 270 nm. To determine t

Olegator [25]

Answer : The percentage reduction in intensity is 79.80 %

Explanation :

Using Beer-Lambert's law :

$A=\epsilon \times C\times l$

$A=\log \frac{I_o}{I}$

$\log \frac{I_o}{I}=\epsilon \times C\times l$

where,

A = absorbance of solution

C = concentration of solution = $3.25mmol.dm^{3-}=3.25\times 10^{-3}mol.dm^{-3}$

l = path length = 2.5 mm = 0.25 cm

$I_o$ = incident light

$I$ = transmitted light

$\epsilon$ = molar absorptivity coefficient = $855dm^3mol^{-1}cm^{-1}$

Now put all the given values in the above formula, we get:

$\log \frac{I_o}{I}=(855dm^3mol^{-1}cm^{-1})\times (3.25\times 10^{-3}mol.dm^{-3})\times (0.25cm)$

$\log \frac{I_o}{I}=0.6947$

$\frac{I_o}{I}=10^{0.6947}=4.951$

If we consider $I_o$ = 100

then, $I=\frac{100}{4.951}=20.198$

Here 'I' intensity of transmitted light = 20.198

Thus, the intensity of absorbed light $I_A$ = 100 - 20.198 = 79.80

Now we have to calculate the percentage reduction in intensity.

$\% \text{reduction in intensity}=\frac{I_A}{I_o}\times 100$

$\% \text{reduction in intensity}=\frac{79.80}{100}\times 100=79.80\%$

Therefore, the percentage reduction in intensity is 79.80 %

3 0

3 years ago

Choose all of the options that demonstrate how humans are impacting the water cycle.

Fantom [35]

Answer:

A.) Air pollutants wash onto land and water bodies from precipitation

C.) Storm water runoff carries pollution

I hope I helped! ^-^

5 0

2 years ago

6.0L of a gas exert a pressure of 2.5 atm. When the pressure is increased to 10.0atm what is the new volume of the gas

jeka57 [31]

Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

$P_1V_1 = P_2V_2$

Since we are finding the new volume

$V_2 = \frac{P_1V_1}{P_2} \\$

From the question we have

$V_2 = \frac{6 \times 2.5}{10} = \frac{15}{10} = \frac{3}{2} \\$

We have the final answer as

Hope this helps you

7 0

2 years ago

Write balanced complete ionic equation for hcl(aq)+lioh(aq)→h2o(l)+licl(aq) express your answer as a chemical equation. identify

Svet_ta [14]

Explanation:

An equation is said to be balanced when the number of atoms on both reactant and product side are equal in number.

Whereas an equation where electrolytes in an aqueous solution are represented as dissociated ions is known as an ionic equation.

For example, $HCl(aq) + LiOH(aq) \rightarrow H_{2}O(l) + LiCl(aq)$ can be represented in ionic form as follows.

$H^{+} + Cl^{-} + Li^{+} + OH^{-} \rightarrow H_{2}O(l) + Li^{+} + Cl^{-}$

Now, cancelling the common ions present on both sides of the equation. The resulting, ionic equation will be as follows.

$H^{+} + OH^{-} \rightarrow H_{2}O(l)$

8 0

3 years ago

Read 2 more answers

Given the following equation, what is the actual yield of potassium chloride if the percent yield is 94% and you have 750 g of o

ivanzaharov [21]

Answer:

ly/3gVQKw3

Explanation:

DON'T PRESS ON THAT LINK PLZ

4 0

3 years ago