All categories

2 years ago

Determine the number of atoms in 73.0 grams of calcium, Ca. (The

1 answer:

7 0

# of atoms per mol = Avogadro’s # (6.022 x 10^23)

Number of mols = mass of substance / molar mass

73 g / 40.08 g = 1.8 mols of Ca in 73 grams

1.8 mols x avagadro’s # = 1.1 x 10^24 atoms in 73 grams of Ca

You might be interested in

What monomer is polymerized to make acrylate? What is the chemical name for this popular polymer?

lawyer [7]

Lucite ,also called plexiglas,British Perspex,trademark name of polymethyl methacrylate.a synthetic organic compound of high molecular weight made by combination of many simple molecules of the ester methyl methacrylate(monomer)into long chains (polymer) the process (polymerization) may be effected by light or etc.

3 0

3 years ago

Read 2 more answers

Given the following sets of values, calculate the unknown

weqwewe [10]

Answer:

3.91 L

Explanation:

Using the ideal gas law equation as follows:

PV = nRT

Where:

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas law constant (0.0821 Latm/molK)

T = temperature (K)

Based on the information given in this question,

P = 5.23 atm

V= ?

n = 0.831 mol

T = 27°C = 27 + 273 = 300K

Using PV = nRT

V = nRT/P

V = (0.831 × 0.0821 × 300) ÷ 5.23

V = 20.47 ÷ 5.23

V = 3.91 L

8 0

3 years ago

Aspirin (C9H8O4) is synthesized by reacting salicylic acid (C7H6O3) with acetic anhydride (C4H6O3). The balanced equation isC7H6

prisoha [69]

Answer:

For a: The mass of acetic anhydride needed is 73.91 grams.

For b: The theoretical yield of aspirin is 130.43 grams.

Explanation:

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

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

For a:

Given mass of salicylic acid = $1.00\times 10^2g=100g$

Molar mass of salicylic acid = 138.121 g/mol

Putting values in equation 1, we get:

$\text{Moles of salicylic acid}=\frac{100g}{138.121g/mol}=0.724mol$

For the given chemical reaction:

$C_7H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+CH_3COOH$

By stoichiometry of the reaction:

1 mole of salicylic acid reacts with 1 mole of acetic anhydride.

So, 0.724 moles of salicylic acid will react with = $\frac{1}{1}\times 0.724=0.724mol$ of acetic anhydride.

Now, to calculate the mass of acetic anhydride, we use equation 1:

Moles of acetic anhydride = 0.724 moles

Molar mass of acetic anhydride = 102.09 g/mol

Putting values in equation 1, we get:

$0.724mol=\frac{\text{Mass of acetic anhydride}}{102.09g/mol}\\\\\text{Mass of acetic anhydride}=73.91g$

Hence, the mass of acetic anhydride needed is 73.91 grams.

For b:

By stoichiometry of the reaction:

1 mole of salicylic acid is producing 1 mole of aspirin.

So, 0.724 moles of salicylic acid will produce = $\frac{1}{1}\times 0.724=0.724mol$ of aspirin.

Now, to calculate the mass of aspirin, we use equation 1:

Moles of aspirin = 0.724 moles

Molar mass of aspirin = 180.158 g/mol

Putting values in equation 1, we get:

$0.724mol=\frac{\text{Mass of aspirin}}{180.158g/mol}\\\\\text{Mass of aspirin}=130.43g$

Hence, the theoretical yield of aspirin is 130.43 grams.

4 0

3 years ago

Which determines how atoms combine to form molecules?

arlik [135]

Will be letter E cause all of them can combine molecule

7 0

3 years ago

How much heat does it take to melt 2.5 kg of lead when it is at its melting point (m.p. = 327.5°C; Hf = 2.04 × 104 J/kg)?

irinina [24]

1. the amount of heat that it would take would be :
5.1 x 10^4 J

2. I think the substance would be : Iron

3. the amount of heat required would be :
1.13 x 10^4 kJ

Hope this helps

6 0

3 years ago

Read 2 more answers