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irina [24]
3 years ago
6

The daily dose for aspirin recommended by doctors is 81 mg/ day to reduce heart disease. a) In a week how many milligrams are ad

ministered? b) Convert the "weekly "milligrams to grams.
Chemistry
1 answer:
V125BC [204]3 years ago
7 0

Answer:

a)567mg

b)0.567 grams

Explanation:

There are 7 days in a week, so we multiply the number of weeks by the number of daily dosage.

81mg*7=567mg

1 gram is 1000 mg

we divide 567 by 1000 to get the value in grams

You might be interested in
8. Ascorbic acid (Vitamin C) cannot be stored in the body, so it must be supplied in the diet. It is a C, H, O compound. If 7.75
spin [16.1K]

Answer:

Molecular formula = C6H8O6

The molar mass of vitamin C = 176.14 g/mol

Explanation:

Step 1: Data given

Mass of vitamin C = 7.75 grams

Mass of CO2 = 11.62 grams

Mass of H2O = 3.17 grams

Molar mass of CO2 = 44.01 g/mol

Molar mass of H2O = 18.02 g/mol

Molar mass C = 12.01 g/mol

Molar mass H = 1.01 g/mol

Molar mass O = 16.0 g/mol

Step 2: Calculate moles CO2

Moles CO2 = 11.62 grams /44.01 g/mol

Moles CO2 = 0.264 moles

Step 3: Calculate moles C

For 1 mol CO2 we have 1 mol C

For 0.264 moles CO2 we have 0.264 moles

Step 4: Calculate mass C

Mass C = 0.264 moles * 12.01 g/mol

Mass C = 3.17 grams

Step 5: Calculate moles H2O

Moles H2O = 3.17 grams / 18.02 g/mol

Moles H2O = 0.176 moles

Step 6: Calculate moles H

For 1 mol H2O we have 2 moles H

For 0.176 moles H2O we have 2*0.176 = 0.352 moles

Step 6: Calculate mass H

Mass H = 0.352 moles * 1.01 g/mol

Mass H = 0.356 grams

Step 7: Calculate mass O

Mass O = 7.75 grams - 3.17 - 0.356

Mass O = 4.224 grams

Step 8: Calculate moles O

Mass O = 4.224 grams / 16.0 g/mol

Mass O = 0.264 moles

Step 9: Calculate mol ratio

We divide by the smallest amount of moles

C: 0.264 moles / 0.264 moles = 1

H: 0.352 moles / 0.264 moles = 1.33

O: 0.264 moles / 0.264 moles = 1

This means for each C atom we have 1.33 H atoms and 1 O atom

OR

For every 3 C atoms we have 4 H atoms and 3 O atoms

The empirical formula is C3H4O3

Step 10: Calculate the molecular formula

The molecular mass of the empirical formula is 88.07

Since the molar mass of vitamin C is between 150 and 200 g/mol

We have to multiply the empirical formula by 2

Molecular formula = 2*(C3H4O3) = C6H8O6

The molar mass of vitamin C = 176.14 g/mol

8 0
3 years ago
Consider a mixture of two gases, A and B, confined in a closed vessel. A quantity of a third gas, C, is added to the same vessel
n200080 [17]

The question is incomplete, here is the complete question:

Consider a mixture of two gases, A and B, confined in a closed vessel. A quantity of a third gas, C, is added to the same vessel at the same temperature. How does the addition of gas C affect the following. The mole fraction of gas B?

A mixture of gases contains 10.25 g of N₂, 2.05 g of H₂, and 7.63 g of NH₃.

<u>Answer:</u> The mole fraction of gas B (hydrogen gas) is 0.557

<u>Explanation:</u>

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

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}     .....(1)

  • <u>For nitrogen gas:</u>

Given mass of nitrogen gas = 10.25 g

Molar mass of nitrogen gas = 28 g/mol

Putting values in equation 1, we get:

\text{Moles of nitrogen gas}=\frac{10.25g}{28g/mol}=0.366mol

  • <u>For hydrogen gas:</u>

Given mass of hydrogen gas = 2.05 g

Molar mass of hydrogen gas = 2 g/mol

Putting values in equation 1, we get:

\text{Moles of hydrogen gas}=\frac{2.05g}{2g/mol}=1.025mol

  • <u>For ammonia gas:</u>

Given mass of ammonia gas = 7.63 g

Molar mass of ammonia gas = 17 g/mol

Putting values in equation 1, we get:

\text{Moles of ammonia gas}=\frac{7.63g}{17g/mol}=0.449mol

Mole fraction of a substance is given by:

\chi_A=\frac{n_A}{n_A+n_B+n_C}

Moles of gas B (hydrogen gas) = 1.025 moles

Total moles = [0.366 + 1.025 + 0.449] = 1.84 moles

Putting values in above equation, we get:

\chi_{(H_2)}=\frac{1.025}{1.84}=0.557

Hence, the mole fraction of gas B (hydrogen gas) is 0.557

6 0
3 years ago
If a sample of oxygen occupies a volume of 85.0 L at a pressure of 67.4 kPa and a temperature of 245K , what volume would the ga
Firdavs [7]

Answer: V2 = 35.54L

Explanation:

Applying

P1= 67.4, V1= 85, T1= 245, P2= 179.6, V2= ?,. T2=273

P1V1/ T1= P2V2/T2

Substitute and simplify

(67.4*85)/245 = (179.6*V2)/273

V2= 35.54L

4 0
3 years ago
Which statement about the gas laws is correct?
Elena-2011 [213]

Answer:

Gay-Lussac's law states that pressure and temperature are directly proportional

Explanation:

Gay-Lussac's law states that pressure and temperature are directly proportional. This always occurs if the volume keeps in constant.

n and V are not directly proportional, they are the same.

At Charles Gay Lussac's law

V1 = V2

n1 = n2

T1 < T2

P1 < P2

P1 / T1 = P2 / T2

If the pressure is contant:

V1 / T1 = V2 /T2

4 0
3 years ago
4 examples of Substances that sublime?
AVprozaik [17]

1. Dry Ice (solid carbon dioxide)

2. Iodine

3. Arsenic

4. Naphthalene

3 0
4 years ago
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