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2 years ago

What is the concentration of a CaBr2 solution if 125.00 g of solute was dissolved in enough water to form 250. ml of solution?

Chemistry

1 answer:

-Dominant- [34]2 years ago

4 0

Answer:

2.50M

Explanation:

Concentration of a solution describes how much of a solute is dissolved in a solvent in a solution. Molarity of a solution is one way to calculate the concentration of a solution.

The Molarity, M is calculated using the formula: number of moles (n) / volume of solution (litres).

To calculate, the number of moles (n), we say that number of moles = mass of solute / molar mass

In this case, CaBr2 (Calcium Bromide) solution is used where mass no of Calcium (Ca) is 40g/mol and Bromine (Br) is 79.9g/mol

Molar mass of CaBr2= 40 + 79.9(2)

40 + 159.8 = 199.8

Hence, molar mass of CaBr2 is 199.8g/mol

Mass of solute= 125grams

Number of moles (n) of CaBr2 = 125/199.8 = 0.6256

n = 0.6256moles

Volume of CaBr2 solution is 250millilitres(ml). Since, 1000ml= 1L, then 250ml is 250/1000 L

= 0.25L

Molarity of solution (M) = number of moles (n)/ volume of solution (litres)

M = 0.6256/0.25

M= 2.5

Thus, the molarity (concentration) of the solution is 2.5M

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mrs_skeptik [129]

Answer:

VP as function of time => VP(Ar) > VP(Ne) > VP(He).

Explanation:

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Review Graham's Law => Effusion Rate ∝ 1/√formula mass.

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2 years ago

If the initial concentration of NOBr is 0.0440 M, the concentration of NOBr after 9.0 seconds is ________. If the initial concen

Nikolay [14]

This is an incomplete question, here is a complete question.

If the initial concentration of NOBr is 0.0440 M, the concentration of NOBr after 9.0 seconds is ________.

The reaction

$2NOBr(g)\rightarrow 2NO(g)+Br_2(g)$

It is a second-order reaction with a rate constant of 0.80 M⁻¹s⁻¹ at 11 °C.

Answer : The concentration of after 9.0 seconds is, 0.00734 M

Explanation :

The integrated rate law equation for second order reaction follows:

$k=\frac{1}{t}\left (\frac{1}{[A]}-\frac{1}{[A]_o}\right)$

where,

k = rate constant = 0.80 M⁻¹s⁻¹

t = time taken = 142 second

[A] = concentration of substance after time 't' = ?

$[A]_o$ = Initial concentration = 0.0440 M

Putting values in above equation, we get:

$0.80M^{-1}s^{-1}=\frac{1}{142s}\left (\frac{1}{[A]}-\frac{1}{(0.0440M)}\right)$

$[A]=0.00734M$

Hence, the concentration of after 9.0 seconds is, 0.00734 M

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2 years ago

What is the melting point of tert-butanol? Besides using a heat lamp, what other options might there be for dispensing a given a

damaskus [11]

Answer:

For dispensing, weigh it out.

Yes, a different solvent such as ethanol could be used.

Explanation:

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In general, a different solvent such as ethanol could be used in place of tert-butanol as long as the solvent is a low molecular weight alcohol.

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2 years ago

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natima [27]

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