All categories

2 years ago

What is the percent mass oxygen in calcium carbonate (CaCo3)?

Chemistry

2 answers:

Naily [24]2 years ago

7 0

20%ca, 80%br is the answer because it is the percent mass oxygen in calcium

Gnoma [55]2 years ago

4 0

<span>Step 1 is to determine the mass of each part
Mass of Ca is 40.08 g
Mass of C is 12.01 g
Mass of O is 16.00 x 3 = 48.00 g
Step 2 is to determine the total mass of the compound
Total mass of CaCO3 is 40.08 + 12.01 + 48.00 = 100.09 g

Step 3 is to determine the % of each part using the following formula:
Mass of part / total mass x 100 =

40.08 / 100.09 x 100 = 40.04 % Ca

12.01 / 100.09 x 100 = 12.00 % C

48.00 / 100.09 x 100 = 47.96 % O

Step 4 is to double check by adding all percentages. If they equal 100, then I probably did it right. :)
40.04
+12.00
+47.96
=100.00</span><span>
</span>

You might be interested in

13. Which statement about trace elements in our atmosphere is false?

tatiyna

Answer: sorry I’m not sure

Odjri:

6 0

2 years ago

(b) The conductivity of a 0.01 mol dm–3 solution of a monobasic organic acid in water is 5.07 × 10–2 S m–1. If the molar conduct

Zarrin [17]

Explanation:

The given data is as follows.

$\Lambda^{o}_{m}$ (NaCl) = $1.264 \times 10^{-2}$

$\Lambda^{o}_{m}$ (H-O=C-ONO) = $1.046 \times 10^{-2}$

$\Lambda^{o}_{m}$ (HCl) = $4.261 \times 10^{-2}$

Conductivity of monobasic acid is $5.07 \times 10^{-2} S m^{-1}$

Concentration = 0.01 $mol/dm^{3}$

Therefore, molar conductivity ( $\Lambda_{m}$ ) of monobasic acid is calculated as follows.

$\Lambda_{m} = \frac{conductivity}{concentration}$

= $\frac{5.07 \times 10^{-2} S m^{-1}}{0.01 mol/dm^{3}}$

= $\frac{5.07 \times 10^{-2} S m^{-1}}{0.01 mol \times 10^{3}}$

= $5.07 \times 10^{-3} S m^{2} mol^{-1}$

Also, $\Lambda^{o}_{m}$ = $\Lambda^{o}_{m}_{(HCl)} + \Lambda^{o}_{m}_{(H-O=C-ONO)} - \Lambda^{o}_{m}_{(NaCl)}$

= $4.261 \times 10^{-2} + 1.046 \times 10^{-2} - 1.264 \times 10^{-2}$

= $4.043 \times 10^{-2} S m^{2} mol^{-1}$

Relation between degree of dissociation and molar conductivity is as follows.

$\alpha = \frac{\Lambda_{m}}{\Lambda^{o}_{m}}$

= $\frac{5.07 \times 10^{-2} S m^{-1}}{4.043 \times 10^{-2} S m^{2} mol^{-1}}$

= 0.1254

Whereas relation between acid dissociation constant and degree of dissociation is as follows.

K = $\frac{c \times \alpha^{2}}{1 - \alpha}$

Putting the values into the above formula we get the following.

K = $\frac{c \times \alpha^{2}}{1 - \alpha}$

= $\frac{0.01 \times (0.1254)^{2}}{1 - 0.1254}$

= $0.017973 \times 10^{-2}$

= $1.7973 \times 10^{-4}$

Hence, the acid dissociation constant is $1.7973 \times 10^{-4}$ .

Also, relation between $pK_{a}$ and $K_{a}$ is as follows.

$pK_{a} = -log K_{a}$

= $-log (1.7973 \times 10^{-4})$

= 3.7454

Therefore, value of $pK_{a}$ is 3.7454.

3 0

2 years ago

Does a displacement reaction take place in 'magnesium + lead nitrate'? and if so why?

cestrela7 [59]

Answer:

Maybe or maybe not (not sure)

Explanation:

A displacement reaction is a type of reaction where one element is displaced by another from a compound.

In the case of magnesium and lead nitrate, magnesium is more reactive than lead. Therefore, it will displace lead from lead nitrate to form magnesium nitrate and lead.

The reaction can be represented as:

Mg(s) + Pb(NO3)2(aq) → Mg(NO3)2(aq) + Pb(s)

Another answer could be;

A displacement reaction does not take place in 'magnesium + lead nitrate' because magnesium is more reactive than lead.

5 0

1 year ago

Which of the following compounds is least soluble in water?

hjlf

Answer:

3) iron (iii) hydroxide

Explanation:

4 0

2 years ago

I NEED HELP!!

solniwko [45]

Carboxylic acids and alcohols have higher boiling point than other hydrocarbons due to their polarity and from the fact that they form very strong intermolecular hydrogen bonding. This is due to the large difference in their electronegativity that forms between the oxygen and the hydrogen atom.

3 0

3 years ago