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4 years ago

The total number of moles represented by 20 grams of CaCO3 is

Chemistry

2 answers:

Mariana [72]4 years ago

7 0

Moles caco3= 20g/100 g/mole=0.2 which is yo answer.

Paul [167]4 years ago

5 0

Moles =CaCo3=20g/100 gm/mol=0.2

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A 13.9 - g piece of metal ( specific heat capacity is 0.449 /g^ C)who whose temperature is 54.2 degrees * C was added to a sampl

lubasha [3.4K]

Answer:

26.2g = Mass of water in the calorimeter

Explanation:

The heat absorbed for the water is equal to the heat released for the metal. Based on the equation:

Q = m*C*ΔT

<em>Where Q is heat, m is the mass of the sample, C is specific heat of the material and ΔT is change in temperature</em>

<em />

Replacing we can write:

$m_{metal}*C_{metal}*dT_{metal}=m_{water}*C_{water}*dT_{water}$

13.9g * 0.449J/g°C * (54.2°C-15.6°C) = m(H₂O) * 4.184J/g°C * (15.6°C-13.4°C)

240.9J = m(H₂O) * 9.2J/g

<h3>26.2g = Mass of water in the calorimeter</h3>

4 0

3 years ago

3. Suppose you wanted to design an experiment to test the composition of a mixture that includes sodium phenoxide (NaC6H5O). You

Liula [17]

Answer:

21.5mL of a 0.100M HCl are required

Explanation:

The sodium phenoxide reacts with HCl to produce phenol and NaCl in a 1:1 reaction.

To solve this question we need to find the moles of sodium phenoxide. These moles = Moles of HCl required to reach equivalence point and, with the concentration, we can find the needed volume as follows:

1.000g * 25% = 0.250g NaC6H5O

<em>Moles NaC6H5O -116.09g/mol-</em>

0.250g NaC6H5O * (1mol/116.09g) = 2.154x10⁻³ moles = Moles of HCl required

<em>Volume 0.100M HCl:</em>

2.154x10⁻³ moles HCl * (1L/0.100mol) = 0.0215L =

<h3>21.5mL of a 0.100M HCl are required</h3>

4 0

3 years ago

Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation is S2(g)+C(s)↽−−⇀CS2(g)????c=9.40 at 900 K Ho

Maru [420]

Answer : The mass of $CS_2$ is, 555.028 grams

Explanation :

First er have to calculate the concentration of $S_2$ .

$\text{Concentration of }S_2=\frac{\text{Moles of }S_2}{\text{Volume of solution}}=\frac{8.08mole}{5.35L}=1.51mole/L$

Now we have to calculate the concentration of $CS_2$ .

The given balanced chemical reaction is,

$S_2(g)+C(s)\rightleftharpoons CS_2(g)$

Initial conc. 1.51 0 0

At eqm. conc. (1.51-x) (x) (x)

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[CS_2]}{[S_2]}$

Now put all the given values in this expression, we get :

$9.40=\frac{x}{(1.51-x)}$

By solving the term 'x', we get :

x = 1.365 M

Concentration of $CS_2$ = x M = 1.365 M

Now we have to calculate the moles of $CS_2$ .

$\text{Moles of }CS_2=\text{Concentration of }CS_2}\times \text{Volume of solution}=1.365mole/L\times 5.35L=7.303mole$

Now we have to calculate the mass of $CS_2$ .

Molar mass of $CS_2$ = 76 g/mole

$\text{Mass of }CS_2=\text{Moles of }CS_2}\times \text{molar mass of }CS_2}=7.303mole\times 76g/mole=555.028g$

Therefore, the mass of $CS_2$ is, 555.028 grams

3 0

4 years ago

Which formula correctly represents the composition of iron III oxide

nikitadnepr [17]

The answer to the question is- Fe2O3

6 0

3 years ago

Which disease is caused by a living pathogen? a. common colds b. smallpox c. cholera d. influenza

liraira [26]

Answer:

Infectious diseases are caused by pathogens, which include bacteria, fungi, protozoa, worms, viruses, and even infectious proteins called prions

7 0

3 years ago