Lidocaine is prepared by the above synthesis. draw the structure of compound a in the sketchpad below.

I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19

IRINA_888 [86]

Answer:

A) Sample B has more calcium carbonate molecules

Explanation:

M = Molar mass of calcium carbonate = 100.0869 g/mol

$N_A$ = Avogadro's number = $6.022\times 10^{23}\ \text{mol}^{-1}$

For the 4.12 g sample

Moles of a substance is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}$

Number of molecules is given by

$nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}$

For the 19.37 g sample

$n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}$

Number of molecules is given by

$nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}$

$1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}$

So, sample B has more calcium carbonate molecules.

The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.

7 0

3 years ago

How many atoms are in 1.75 mol CHCL3

vaieri [72.5K]

1 mol = 6.022 x 10²³ atoms

In order to find how many atoms, dimly multiply the amount of moles you have by 6.022 x 10²³ or Avogadro's number.

So you have 1.75 mol CHC1₃ x (6.022x10²³) = 1.05385 x 10²⁴ atoms of CHCl₃

But now you have to round because of the rules of significant figures so you get 1.05 x 10²⁴ atoms of CHCl₃

6 0

3 years ago

Read 2 more answers

An obese man was discovered in his air-conditioned hotel room sitting in a chair in front of the television. The air conditioner

Leno4ka [110]

Answer:

It has been approximately 6 hours after death.

Explanation:

This is because between 2-6 hours after death, the body starts becoming stiff from top to bottom, then spreading to the limbs. Since there is only rigor in his upper body, that would mean that with normal temperature and body conditions, it would be 4 or 5 hours after death. But since he is obese and in cold temperature, there is slower progression of rigor, leading to the maximum time in the first rigor mortis phase, 6 hours.

8 0

3 years ago

What is the amount of aluminum chloride produced from 40 moles of aluminum and excess chlorine?

Marrrta [24]

Answer:

is it 26.98

Explanation:

6 0

3 years ago

when copper sulfide is partially roasted in air (reaction with o2), copper sulfite is formed first. subsequently, upon heating,

Lyrx [107]

The question is incomplete, complete question is:

When copper(I) sulfide is partially roasted in air (reaction with oxygen), copper(I) sulfite is formed first. subsequently, upon heating, the copper sulfite thermally decomposes to copper(I) oxide and sulfur dioxide. Write balanced chemical equations for these two reactions.

Answer:

The balanced chemical equations for these two reactions:

$2Cu_2S(s)+3O_2(g)\rightarrow 2Cu_2SO_3(s)$

$Cu_2SO_3(s)\overset{heat}\rightarrow Cu_2O(s)+SO_2(g)$

Explanation:

On partial roasting of copper sulfide in an air. The balanced chemical reaction is given as:

$2Cu_2S(s)+3O_2(g)\rightarrow 2Cu_2SO_3(s)$

On further heating of copper(I) sulfite it get decomposes into copper oxide and sulfur dioxide. The balanced chemical reaction is given as:

$Cu_2SO_3(s)\overset{heat}\rightarrow Cu_2O(s)+SO_2(g)$

5 0

3 years ago