How are water molecules able to weakly bond to one another with hydrogen bonds?

How much energy is absorbed when 10 grams of gold increases in

ra1l [238]

Answer:

6.45 joules

Explanation:

energy=10×(55-50)×0.129

=1.29×5

=6.45 J

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7 0

3 years ago

A device that does work with only one movement is a simple machine true or false

Rainbow [258]

Answer:

true

Explanation:

8 0

3 years ago

What are the uses of glycerin?

Ilia_Sergeevich [38]

Explanation:

This medication is used as a moisturizer to treat or prevent dry, rough, scaly, itchy skin and minor skin irritations (e.g., diaper rash, skin burns from radiation therapy). Emollients are substances that soften and moisturize the skin and decrease itching and flaking.

6 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

What is the vapor pressure of an aqueous solution made up of 60.0g of urea (CH4N2O) in 180g of water? the vapor pressure of wate

djyliett [7]

To get the answer you use the Law of Raoult.

Raoult's law states that the decrease of the vapor pressure of a liquid is proportional to the molar fraction of the solute.

ΔP = Pa * Xa

Here Pa = 0.038 atm

And Xa = N a / (Na + Nb), where Na is number of moles of A and Nb is number of moles of b

Na = mass of urea / molar mass of urea = 60 g / (molar mass of CH4N2O)

molar mass of CH4N2O = 12 g/mol + 4*1g/mol + 2*14 g/mol + 16 g/mol = 60 g/mol

Na = 60 g / 60 g/mol = 1 mol

Nb = mass of water / molar mass of water = 180g / 18g/mol = 10 mol

Xa = 1 mol / (10 mol + 1 mol) = 1/11 =0.09091

ΔP = Pb * Xa = 0.038 atm * 0.09091 = 0.0035 atm

Then, the final vapor pressure of water is Pb - ΔP = 0.038atm - 0.0035atm = 0.035 atm.

Answer: 0.035 atm

7 0

4 years ago