Which of the following substances dissolves most readily in water?

photoshop1234 [79]

I think it could be C maybeee though

6 0

3 years ago

A student is given a 2.002 g sample of unknown acid and is told that it might be butanoic acid, a monoprotic acid (HC4H7O2, equa

Elina [12.6K]

Answer: The identity of the unknown acid is butanoic acid or ascorbic acid.

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}$

Molarity of NaOH solution = 0.570 M

Volume of solution = 39.55 mL

Putting values in above equation, we get:

$0.570M=\frac{\text{Moles of NaOH}\times 1000}{39.55}\\\\\text{Moles of NaOH}=\frac{0.570\times 39.55}{1000}=0.0225mol$

The chemical equation for the reaction of NaOH and monoprotic acid follows:

$NaOH+HX\rightarrow NaX+H_2O$

By Stoichiometry of the reaction:

1 mole of NaOH reacts with 1 mole of HX

So, moles of monoprotic acid = 0.0225 moles

The chemical equation for the reaction of NaOH and diprotic acid follows:

$2NaOH+H_2X\rightarrow 2NaX+2H_2O$

By Stoichiometry of the reaction:

2 moles of NaOH reacts with 1 mole of diprotic acid

So, moles of diprotic acid = $\frac{0.0225}{2}=0.01125moles$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

For butanoic acid:

Mass of butanoic acid = 2.002 g

Molar mass of butanoic acid = 88 g/mol

Putting values in above equation, we get:

$\text{Moles of butanoic acid}=\frac{2.002g}{88g/mol}=0.02275mol$

For L-tartaric acid:

Mass of L-tartaric acid = 2.002 g

Molar mass of L-tartaric acid = 150 g/mol

Putting values in above equation, we get:

$\text{Moles of L-tartaric acid}=\frac{2.002g}{150g/mol}=0.0133mol$

For ascorbic acid:

Mass of ascorbic acid = 2.002 g

Molar mass of ascorbic acid = 176 g/mol

Putting values in above equation, we get:

$\text{Moles of ascorbic acid}=\frac{2.002g}{176g/mol}=0.01137mol$

As, the number of moles of butanoic acid and ascorbic acid is equal to the number of moles of acid getting neutralized.

Hence, the identity of the unknown acid is butanoic acid or ascorbic acid.

5 0

3 years ago

At exactly 2:00 PM, speedy the hermit crab crawl onto a meter stick starting at the 10 cm mark. If he reaches the 60 cm mark at

kvv77 [185]

Answer:

speed=5cm/minute

Explanation:

Given at 2:00PM the hermit is at 10cm mark

Also given that the hermit reaches 60cm mark at 2:10PM

Therefore the time elapsed is 10 minutes = $10\times 60=600 seconds$

the distance travelled by the hermit is 60-10=50cm=0.5m

We know that

$speed=\frac{distane}{time}$

$speed=\frac{0.5}{600}$

speed = $8.3\times 10^{-4}$ m/sec=5cm/minute

3 0

3 years ago

Something that is made out of natural resources for human use is called

ANEK [815]

Answer:

Man-made resources

Explanation:

Humanized resources are items or substances that have value to human lives that do not occur in the natural world. Examples of man-made resources include plastic, paper, soda, sheet metal, rubber and brass. These contrast with natural resources, such as water, crops, sunlight, crude oil, wood and gold.

6 0

3 years ago

Explain the volume of ideal gasses as related to the molar concept.

horrorfan [7]

Answer:

n = Initial volume/22.4L

Explanation:

The molar concept is simply one that is used to find the Number of moles and explain the relationship it has with avogadro's number, molecular mass, molar mass e.t.c.

Now, in terms of molar mass, number of moles is given by the formula;

n = mass of the sample/molar mass

In terms of avogadro's number, number of moles is;

1 mole = avogadro's number = 6.02 × 10^(23)

Now, when dealing with ideal gases, the molar volume of an ideal gas is 22.4 L.

Now the relationship between this volume and the mole concept is that the number of moles is gotten by dividing the initial volume by this molar volume.

Thus;

n = Initial volume/22.4L

6 0

3 years ago