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2 years ago

If a sample of sodium chloride with a mass of

1 answer:

6 0

Original molarity was 1.7 moles of NaCl

Final molarity was 0.36 moles of NaCl

Given Information:

Original (concentrated) solution: 25 g NaCl in a 250 mL solution, solve for molarity

Final (diluted) solution: More water is added to make the new total volume 1.2 liters, solve for the new molarity

1. Solve for the molarity of the original (concentrated) solution.

Molarity (M) = moles of solute (mol) / liters of solution (L)

Convert the given information to the appropriate units before plugging in and solving for molarity.

Molarity (M) = 0.43 mol NaCl solute / 0.250 L solution = 1.7 M NaCl (original solution)

2. Solve for the molarity of the final (diluted) solution.

Remember that the amount of solute remains constant in a dilution problem; it is just the total volume of the solution that changes due to the addition of solvent.

Molarity (M) = 0.43 mol NaCl solute / 1.2 L solution

Molarity (M) of the final solution = 0.36 M NaCl

I hope this helped:))

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What is the volume of an object with a mass of 31g and density of 444g/ml

Tanzania [10]

Answer:

<h2>The answer is 0.07 mL</h2>

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

$volume = \frac{mass}{density} \\$

From the question

mass = 31 g

density = 444 g/mL

We have

$volume = \frac{31}{444} \\ = 0.06981...$

We have the final answer as

Hope this helps you

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2 years ago

Write a mechanism for the esterification of propanoic acid with 18O-labeled ethanol. Show clearly the fate of the 18O label. (b)

tatuchka [14]

Answer:

See explanation and images attached

Explanation:

a) In the mechanism for the acid catalysed esterification of propanoic acid using ethanol, we can see that the first step is the protonation of the acid followed by nucleophillic attack of the alcohol. Loss of water and consequent deprotonation regenerates the acid catalyst. We can see the fate of the 18O labelled ethanol in the mechanism shown.

b) In the second mechanism, an unnamed ester is hydrolysed using an acid catalyst. The attack of the acid and subsequent nucleophillic attack of water labelled with 18O leads to the incorporation of this 18O into the product acid as shown in the mechanism attached to this answer.

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2 years ago

Consider the following equation. 2H2(g) + O2(g) 2H2O(g); ΔH is negative. Which statement is true? The reaction is endothermic fr

Svetradugi [14.3K]

Answer is: Increased pressure would increase the rate of forming water vapor.

According to Le Chatelier's Principle, the position of equilibrium moves to counteract the change, the position of equilibrium will move so that the concentration of products (water waper) of chemical reaction increase, if:

1) decrease temperature, because this is exothermic reaction (ΔH is negative).

2) increase concentration of reactants (oxygen and hydrogen).

3) increase pressure of the system, so reaction moves to direction where is less molecules.

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2 years ago

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A baby weighs 7 pounds, 4 ounces at birth and 7 pounds, I ounce at discharge. What percent of weight did the baby lose

Aloiza [94]

Answer:

2.6%

Explanation:

As, 1 ounce (oz) = 0.0625 pounds (lb)

Therefore, weight of baby at discharge = 7 lb,1 oz = 7+0.0625 lb = 7.0625 lb

Since, 1 oz = 0.0625 lb

⇒ 4 oz = 4×0.0625 = 0.25 lb

Therefore, weight of baby at birth = 7 lb,4 oz = 7+0.25 lb = 7.25 lb

The amount of weight lost is equal to the difference of weight of the baby at birth and discharge.

Therefore, weight lost = 7.25 lb - 7.0625 lb = 0.1875 lb

Now, the percentage of weight lost by the baby is given by the amount of weight lost divided by the weight of the baby at birth.

Therefore, the percentage of weight lost = weight lost ÷ weight at birth = 0.1875 lb ÷ 7.25 lb × 100 = 2.6%

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3 years ago

What are some uses for graphite

erma4kov [3.2K]

Because it is a solid material, it is known as a dry lubricant. This is useful inapplications where “wet” lubricants, such as oil, cannot be used. Graphite is the only non-metal element that is a good conductor of electricity. Natural graphite is used mostly in what are called refractory applications

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3 years ago