I believe that the answer would be D, both the speaker and the microphone
Percentage by mass is the mass of NaF present in 100 g of the solution.
the percentage by mass of NaF is 23.4 %
this means that in 100 g of solution, mass of NaF present is 23.4 g
the number of moles of NaF present - 1.33 mol
mass of NaF - 1.33 mol x 42 g/mol = 55.9 g
when there's 23.4 g of NaF - mass of solution is 100 g
therefore when there's 55.9 g of NaF - mass of solution is 100 / 23.4 x 55.9
= 239 g
mass of solution required is 239 g
Answer:
The correct option is: 2.50 g
Explanation:
Reaction involved: Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)
Molar mass: Mg = 24.305 g/mol, HCl = 36.461 g/mol
In the given reaction, 1 mole Mg reacts with 2 moles HCl.
Given: mass of HCl = 7.50 g
So, the number of moles of HCl = given mass ÷ molar mass = 7.50 g ÷ 36.461 g/mol = 0.2057 moles
Therefore, the<u> number of moles of Mg</u> that reacts with 0.2057 mole HCl = 0.2057 ÷ 2 = 0.1028 moles
Therefore, <u>the mass of Mg in grams</u> = molar mass × number of moles = 24.305 g/mol × 0.1028 mole = 2.5 g
2)NCl3
4)N2O3
5)NH3
6)B2H2
7)K3P
8)OF2
9)Mg(NO3)2
10)Al2(CO3)3
