Answer: Option (A) is the correct answer.
Explanation:
It is known that when sharing of electrons take place between two combining atoms then the bond formed is known as a covalent bond. In general, a covalent bond is formed between two non-metal atoms.
For example, the compound HCl has a covalent bond between the hydrogen and chlorine atom. As hydrogen atom has 1 valence electron and chlorine atom has 7 valence electrons.
So, in order to attain stability both these atoms will share their valence electrons and hence, a covalent bond is formed.
On the other hand, when an electron is transferred from one atom to another then it tends to form an ionic bond.
For example, the compound NaCl has an ionic bond.
Thus, we can conclude that when atomic orbitals of two nuclei overlap, the mutual attraction between a negatively charged electron pair and the two positively charged nuclei forms a covalent bond.
For pure water the PH level is 7
Answer: a heterogenous mixture is simply any mixture that is not uniform in composition- its non-uniform mixture of smaller constituent parts
Explanation:
Answer : The mass of 
required is 18.238 grams.
Explanation : Given,
Mass of 
= 83.10 g
Molar mass of = 146 g/mole
Molar mass of = 256.52 g/mole
The balanced chemical reaction is,
First we have to determine the moles of .
Now we have to determine the moles of .
From the balanced chemical reaction we conclude that,
As, 8 moles of produced from 1 mole of
So, 0.569 moles of produced from 
mole of
Now we have to determine the mass of .
Therefore, the mass of required is 18.238 grams.
Answer:
Mass = 112 g
Explanation:
Given data:
Mass of CO₂ produced = 90.6 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂+ 4H₂O
Number of moles of CO₂:
Number of moles = 90.6 g/ 44 g/mol
Number of moles = 2.1 mol
Now we will compare the moles of CO₂ and oxygen:
CO₂ : O₂
3 : 5
2.1 : 5/3×2.1 = 3.5
Mass of oxygen needed:
Mass = number of moles × molar mass
Mass = 3.5 mol × 32 g/mol
Mass = 112 g
