All categories

2 years ago

Calculate the mass of sample of calcium carbonate containing 5.5 x 10^23 atoms

Chemistry

1 answer:

Amiraneli [1.4K]2 years ago

5 0

No of moles:-

No of molecules/Avagadro no
5.5×10²³÷6.022×10²³
0.91mol

Now

molar mass:-

CaCO_3
40+12+48
100g/mol

Mass:-

100(0.91)
91g

Option B

You might be interested in

During an investigation, hair samples are taken from either the head or pubic area of a victim.

BabaBlast [244]

Answer:

A. True

Explanation:

it is possible to identify a hair as originating from a particular body area, the regions of the body that are primarily used in forensic comparisons are the head and pubic areas.

Forensic = the application of scientific methods and techniques to natters investigation by a court of law.

7 0

2 years ago

Given the following information: Mass of proton = 1.00728 amu Mass of neutron = 1.00866 amu Mass of electron = 5.486 × 10^-4 amu

lesya692 [45]

<u>Answer:</u> The nuclear binding energy of the given element is $2.938\times 10^{12}J/mol$

<u>Explanation:</u>

For the given element $_3^6\textrm{Li}$

Number of protons = 3

Number of neutrons = (6 - 3) = 3

We are given:

$m_p=1.00728amu\\m_n=1.00866amu\\A=6.015126amu$

M = mass of nucleus = $(n_p\times m_p)+(n_n\times m_n)$

$M=[(3\times 1.00728)+(3\times 1.00866)]=6.04782amu$

Calculating mass defect of the nucleus:

$\Delta m=M-A\\\Delta m=[6.04782-6.015126)]=0.032694amu=0.032694g/mol$

Converting this quantity into kg/mol, we use the conversion factor:

1 kg = 1000 g

So, $0.032694g/mol=0.032694\times 10^{-3}kg/mol$

To calculate the nuclear binding energy, we use Einstein equation, which is:

$E=\Delta mc^2$

where,

E = Nuclear binding energy = ? J/mol

$\Delta m$ = Mass defect = $0.032694\times 10^{-3}kg/mol$

c = Speed of light = $2.9979\times 10^8m/s$

Putting values in above equation, we get:

$E=0.032694\times 10^{-3}kg/mol\times (2.9979\times 10^8m/s)^2\\\\E=2.938\times 10^{12}J/mol$

Hence, the nuclear binding energy of the given element is $2.938\times 10^{12}J/mol$

3 0

3 years ago

An atom has an 16 protons, 18 neutrons, and 13 electrons. What are its atomic number, atomic mass, and net charge?

Lemur [1.5K]

Answer:

Atomic number = 16, Atomic mass = 34, Net charge= +3

Explanation:

i) Atomic number = Proton number = 16

ii) Atomic mass = Proton number + Neutron number

= 16 + 18 = 34

iii) Net charge= Proton number = Electron number (when element is in ground state or unreacted state)

But, proton number (16) is not the same as electron number (13), this means the element has lost 3 electrons

Thereore, the net charge is = 16-13

= +3

7 0

3 years ago

This element has 3 electrons in its Lewis dot structure and is in the 2p orbital section

Ulleksa [173]

Hen two electrons occupy the same orbital, they always have opposite spin. No other knowledge about electron spin is needed for A-level.) Only when the 2s is filled, can the 2p sub-level fill. With the next six elements (boron, carbon, nitrogen, oxygen, fluorine and neon) the three 2p orbitals are filled.

3 0

4 years ago

Which of the following is not a sign that a chemical change has occurred?

fredd [130]

Your answer is change in mass :D

3 0

4 years ago