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2 years ago

Helppppp with this pleasee

Chemistry

1 answer:

vazorg [7]2 years ago

3 0

Answer:

A. 1, 2, 5

Explanation:

Count the number of Ns in the formula.

- Hope that helped! Please let me know if you need a further explanation.

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Question 3 (1 point) The extinction coefficient for copper sulfate in aqueous solution is 12 M-1.cm-1 at 800 nm. If the absorban

Troyanec [42]

Answer:

The concentration of the copper sulfate solution is 83 mM.

Explanation:

The absorbance of a copper sulfate solution can be calculated using Beer-Lambert Law:

A = ε . c . <em>l</em>

where

ε is the extinction coefficient of copper sulfate (ε = 12 M⁻¹.cm⁻¹)

c is its molar concentration (what we are looking for)

l is the pathlength (0.50 cm)

We can use this expression to find the molarity of this solution:

$c=\frac{A}{\epsilon.l } =\frac{0.5}{12M^{-1}cm^{-1}0.50cm } =0.083M=83mM$

3 0

2 years ago

It is required to prepare 1250 kg of a solution composed of 12 wt.% ethanol and 88 wt.% water. Two solutions are available, the

bekas [8.4K]

Answer:

437.5 kg of first solution and 812.5 kg of second solution should be mixed to get desired solution.

Explanation:

Let the mass of the first solution be x and second solution be y.

Amount solution required = 1250 kg

x + y = 1250 kg....[1]

Percentage of ethanol in required solution = 12% of 1250 kg

Percentage of ethanol in solution-1 = 5% of x

Percentage of ethanol in required solution = 25% of y

5% of x + 25% of y =12% of 1250 kg

$\frac{5}{100}\times x+\frac{25}{100}y=\frac{12}{100}\times 1250 kg$

x + 5y = 3000 kg...[2]

Solving [1] and [2] we :

x = 437.5 kg , y = 812.5 kg

437.5 kg of first solution and 812.5 kg of second solution should be mixed to get desired solution.

8 0

2 years ago

What mass would release 2620J of heat when cooled 50 degrees C?

OverLord2011 [107]

the answer is B)12.5

7 0

3 years ago

Read 2 more answers

The rate law for the reaction

juin [17]

Explanation:

Since, the given reaction is as follows.

$2NO(g) + Cl_{2}(g) \rightarrow 2NOCl(g)$

Hence, rate law of the reaction is as follows.

R = $k[NO][Cl_{2}]$

As it is known that rate of a reaction depends on the initial concentration of products. So here, the rate of reaction will depend on the concentration of NO and $Cl_{2}$ . Since, power of the concentrations of each of these is equal to 1. Therefore, order of the reaction is equal to 1 + 1 = 2.

According to the rate law, reactants involved in the rate determining step are NO and $Cl_{2}$ . Hence, first step of the mechanism is the rate determining step.

Also, according to the rate of reaction doubling the concentration of NO will double the rate of reaction.

The number of reactants taking part in a single step of the reaction is known as molecularity of the reaction. Therefore, molecularity of the first step of the reaction is 2.

Both the given steps are not termolecular.

5 0

3 years ago

A 6.68-g aqueous solution of isopropyl alcohol contains 3.97 g of isopropyl alcohol. What is the mass percentage of isopropyl al

Sphinxa [80]

Answer : The mass percentage of isopropyl alcohol in the solution is, 59.4 %

Explanation :

To calculate the mass percentage of isopropyl alcohol in the solution, we use the equation:

$\text{Mass percent of isopropyl alcohol}=\frac{\text{Mass of isopropyl alcohol}}{\text{Mass of isopropyl alcohol solution}}\times 100$

Mass of isopropyl alcohol = 6.68 g

Mass of isopropyl alcohol solution = 3.97 g

Putting values in above equation, we get:

$\text{Mass percent of isopropyl alcohol}=\frac{3.97g}{6.68g}\times 100=59.4\%$

Thus, the mass percentage of isopropyl alcohol in the solution is, 59.4 %

6 0

2 years ago