Answer:
The answer to your question is: 2.20 x 10 ²³ molecules
Explanation:
Data
mass = 45.7 g
molecules of CF₂Cl₂ = ?
Process
1.- Calculate the mass number of CF₂Cl₂
C = 12 F =2 x 19 Cl = 2 x 35.5
total = 12 + 38 + 71
total = 121 g
2.- Use the Avogradro's number to solve the problem
121 g ------------------- 6.023 x 10²³ molecules of CF₂Cl₂
45.7 g --------------- x
x = (45.7 x 6.023 x 10²³) / 121
x = 2.75 x 10²⁵ / 121
x = 2.20 x 10 ²³ molecules
The three sub-atomic particles that made up an atom are electron, proton and neutron. The proton and neutron are present in the nucleus of an atom whereas electrons revolve around the nucleus in the orbits. The atoms are electrically neutral that is they have no charge due to the presence of equal number of protons (which is positively charged) and electrons (which is negatively charged).
All the atoms have negatively charged electrons which are counter balanced by the presence of equal number of protons in the nucleus of an atom and thus, the element is neutral in nature and possess no charge.
The empirical formula :
C₁₀H₁₆N₄SO₇
<h3>Further explanation</h3>
Given
6.4 g sample
Required
The empirical formula
Solution
mass C :
= 12/44 x 8.37 g
= 2.28
mass H :
= 2/18 x 2.75 g
= 0.305
mass N = 1.06
mass S :
= 32/64 x 1.23
= 0.615
mass O = 6.4 - (2.28+0.305+1.06+0.615) = 2.14 g
Mol ratio :
= C : H : N : S : O
= 2.28/12 : 0.305/1 : 1.06/14 : 0.615/32 : 2.14/16
= 0.19 : 0.305 : 0.076 : 0.019 : 0.133 divided by 0.019
= 10 : 16 : 4 : 1 : 7
The empirical formula :
C₁₀H₁₆N₄SO₇
To answer the questions,
(1) Activation energy is the amount of energy that is needed for the reaction to proceed, converting the reactant to products. The answer is letter B.
(2) The rate of chemical reaction normally increases as the reactant concentration is increased. The answer is letter C.
