Si un gaz exerce une pression de 2,00 atm lorsque 20 bouffées de particules sont présentes alors pour 4,50 atm il faut 45 bouffées car 20 bouffées = 2,00 atm donc 2*20=40 +0,5 =4,50
Answer:
6.69%
Explanation:
Given that:
Mass of the fertilizer = 0.568 g
The mass of HCl used in titration (45.2 mL of 0.192 M)
= 
= 0.313 g HCl
The amount of NaOH used for the titration of excess HCl (42.4 mL of 0.133M)
= 
= 0.0058919 mole of NaOH
From the neutralization reaction; number of moles of HCl is equal with the number of moles of NaOH is needed to complete the neutralization process
Thus; amount of HCl neutralized by 0.0058919 mole of NaOH = 0.0058919 × 36.5 g
= 0.2151 g HCl
From above ; the total amount of HCl used = 0.313 g
The total amount that is used for complete neutralization = 0.2151 g
∴ The amount of HCl reacted with NH₃ = (0.313 - 0.2151)g
= 0.0979 g
We all know that 1 mole of NH₃ = 17.0 g , which requires 1 mole of HCl = 36.5 g
Now; the amount of HCl neutralized by 0.0979 HCl = 
= 0.0456 g
Therefore, the mass of nitrogen present in the fertilizer is:
= 
= 0.038 g
∴ Mass percentage of Nitrogen in the fertilizer =
%
= 6.69%
Answer: The chemical equations are given below.
Explanation:
A balanced chemical reaction follows law of conservation of mass.
This law states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form. This also means that total number of individual atoms on reactant side must be equal to the total number of individual atoms on the product side.
Single displacement reaction is defined as the reaction in which more reactive metal displaces a less reactive metal from its chemical reaction.
General equation representing single displacement reaction follows:

C is more reactive element than element A.
The reactivity of metals is judged by the series known as reactivity series. Elements lying above in the series are more reactive than the elements lying below in the series.
- 1. When solid lead metal is put in the beaker of 0.043 M
solution.
Lead lies below in the reactivity series than iron. Thus, it will not replace iron from its chemical reaction.

- 2. When solid iron metal is put in the beaker of 0.044 M
solution.
Iron lies above in the reactivity series than lead. Thus, it will easily replace lead from its chemical reaction.

Hence, the chemical equations are given above.
Answer: E. 78%
Explanation:
Diborane (B2H6), a chemical compound made up of approximately 78% Boron and 22% Hydrogen.