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3 years ago

What is the mass of 0.25 moles of water? O 0.25 g 4.5 g 18 g 72g

Chemistry

1 answer:

Dahasolnce [82]3 years ago

5 0

Answer:

4.5 g

Explanation:

The mass of 1 mol of water is 18.02 g.

$\text{Mass of H$_{2}$O} = \text{0.25 mol H$_{2}$O} \times \dfrac{\text{18.02 g H$_{2}$O}}{\text{1 mol H$_{2}$O}} = \textbf{4.5 g H$_{2}$O}$

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A 0.43g samle of KHP required 24.11cm of NaOH for neutralization. Calculate the molarity of NaOH

expeople1 [14]

Answer:

0.083 M

Explanation:

We'll begin by calculating the number of mole in 0.43 g of KHP (potassium hydrogen phthalate, C₈H₅O₄K). This is can be obtained as follow:

Mass of C₈H₅O₄K = 0.43 g

Molar mass of C₈H₅O₄K = (8×12) + (5×1) + (16× 4) + 39

= 96 + 5 + 64 + 39 = 204 g/mol

Mole of C₈H₅O₄K =?

Mole = mass / molar mass

Mole of C₈H₅O₄K = 0.43 / 204

Mole of C₈H₅O₄K = 0.002 mole

Next, we shall determine the number of mole of NaOH required to react with 0.43 g (i.e 0.002 mole) of KHP. This can be obtained as follow:

C₈H₅O₄K + NaOH → C₈H₄O₄KNa + H₂O

From the balanced equation above,

1 mole of KHP reacted with 1 mole of NaOH.

Therefore, 0.002 mole of KHP will also react with 0.002 mole of NaOH.

Next, we shall convert 24.11 cm³ to L. This can be obtained as follow:

1000 cm³ = 1 L

Therefore,

24.11 cm³ = 24.11 cm³ × 1 L / 1000 cm³

24.11 cm³ = 0.02411 L

Finally, we shall determine the molarity of NaOH. This can be obtained as follow:

Mole of NaOH = 0.00 2 mole

Volume = 0.02411 L

Molarity of NaOH =?

Molarity = mole /Volume

Molarity of NaOH = 0.002 / 0.02411

Molarity of NaOH = 0.083 M

3 0

3 years ago

96.0 g. of a gas occupies 48.0 L at 700.0 mm Hg and 20.0 °C. What is its molecular weight?

g100num [7]

Answer:

I hope this helps 52.2 g/mol

Explanation:

1) Solve for the moles using PV = nRT:

n = PV / RT

n = [(700.0 mmHg / 760.0 mmHg atm¯1) (48.0 L)] / [(0.08206 L atm mol¯1 K¯1) (293.0 K)]

n = 1.8388 mol

2) Divide the grams given (96.0) by the moles just calculated above:

96.0 g / 1.8388 mol = 52.2 g/mol

7 0

3 years ago

Shaun's doctor has recommended that he consume 200 calories of protein a day. Shaun consumed 176 calories of protein in one day.

evablogger [386]

Answer: Shaun must consume 6 more g of protein to reach the required amount.

Explanation:

Given : Recommended amount of protein = 200 calories

Now 4 calories = 1 gram of protein

Thus 200 calories = $\frac{1}{4}\times 200=50$ g of protein.

Calories consumed per day by Shaun = 176 calories

176 calories = $\frac{1}{4}\times 176=44$ g of protein.

Thus Shaun need to consume = (50-44) g = 6 of protein to reach the required amount.

Shaun must consume 6 more g of protein to reach the required amount.

5 0

3 years ago

How many grams of H2S is needed to produce 18.00g of PbS if the H2S is reacted with an

goldenfox [79]

Answer:

2.56 grams of H₂S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH₃COO)₂

Explanation:

The balanced reaction is:

Pb(CH₃COO)₂ + H₂S → 2 CH₃COOH + PbS

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) they react and produce:

Pb(CH₃COO)₂: 1 mole
H₂S: 1 mole
CH₃COOH: 2 moles
PbS: 1 mole

In this case, to know how many grams of H₂S are needed to produce 18.00 g of PbS, it is first necessary to know the molar mass of the compounds H₂S and PbS and then to know how much it reacts by stoichiometry. Being:

H: 1 g/mole
S: 32 g/mole
Pb: 207 g/mole

The molar mass of the compounds are:

H₂S: 2* 1 g/mole + 32 g/mole= 34 g/mole
PbS: 207 g/mole + 32 g/mole= 239 g/mole

So, by stoichiometry they react and are produced:

H₂S: 1 mole* 34 g/mole= 34 g
PbS: 1 mole* 239 g/mole= 239 g

Then the following rule of three can be applied: if 239 grams of PbS are produced by stoichiometry from 34 grams of H₂S, 18 grams of PbS from how much mass of H₂S is produced?

$mass of H_{2} S=\frac{18 grams of PbS*34 grams of H_{2}S }{239 grams of PbS}$

mass of H₂S= 2.56 grams

<u><em>2.56 grams of H₂S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH₃COO)₂</em></u>

8 0

4 years ago

Which type of cell does mitosis produces?

frosja888 [35]

Answer:

animal and plant cells

5 0

3 years ago

Read 2 more answers