We know that
pH = -log[H+]
the pH value falls in between 0- 7 for acids
As the pH value increases the concentration of [H+] increases.
similarly as the value of pH approaches 0, the concentration of H+ increases
The solution said to become more acidic
Also
[H+] X [OH-] = 10^-14
Thus pH + pOH = 14
hence the concentration of OH- decreases as the pH approaches zero
Explanation:
4. limestone heat lime + carbon dioxide
The reactants in this expression above is limestone
The products of the reaction is carbon dioxide and lime
Reactant is the species that gives the product and it is usually found on the left hand side of the expression.
The product is the substance on the right hand side of the expression that forms through the experiment.
Heat is used to facilitate the reaction.
5. An exothermic reaction is a reaction in which heat is given off.
An endothermic reaction is a reaction in which heat is absorbed in the process.
An exothermic reaction is always warmer after the reaction whereas an endothermic reaction is colder at the end of the reaction.
Answer: Option (D) 30N
Detailed Solution:
According to Newton's second law:
F = ma --- (A)
Given:
mass = 5kg
acceleration = 6 m/s^2
F = ?
Plug all the value in equation (A)
F = (5)(6)
Ans: F = 30N
Answer:
0.6 grams of hydrogen are needed to react with 2.75 g of nitrogen.
Explanation:
When hydrogen and nitrogen react they form ammonia.
Chemical equation:
N₂ + 3H₂ → 2NH₃
Given mass of nitrogen = 2.75 g
Number of moles of nitrogen:
Number of moles = mass/ molar mass
Number of moles = 2.75 g / 28 g/mol
Number of moles = 0.098 mol
Now we will compare the moles of nitrogen with hydrogen from balance chemical equation:
N₂ : H₂
1 : 3
0.098 : 3×0.098 = 0.3 mol
Mass of hydrogen:
Mass = number of moles × molar mass
Mass = 0.3 mol × 2 g/mol
Mass = 0.6 g
