Answer is: 3,4
Chemical reaction: HNO₂ + NaOH → NaNO₂ + H₂O.
c₀(HNO₂) = 1,2 M = 1,2 mol/dm³.
c₀(NaNO₂) = 0,8 M = 0,8 mol/dm³.
V₀(HNO₂) = V₀(NaNO₂) = 1 dm³ = 1 L.
c₀(NaOH) = 0,5 M = 0,5 mol/dm³.
n₀(HNO₂)= 1,2 mol/dm³ · 1 dm³ = 1,2 mol.
n₀(NaNO₂) = 0,8 mol/dm³ · 1 dm³ = 0,8 mol.
V(NaOH) = 400 mL · 0,001 dm³/mL = 0,4 dm³.
n₀(NaOH) = c₀(NaOH) · V₀(NaOH).
n₀(NaOH) = 0,5 mol/dm³ · 0,4 dm³ = 0,2 mol.
n(HNO₂) = 1,2 mol - 0,2 mol = 1 mol.
n(NaNO₂) = 0,8 mol + 0,2 mol = 1 mol.
c(HNO₂) = 1 mol ÷ 1,4 dm³ = 0,714 mol/dm³.
c(NaNO₂) = 1 mol ÷ 1,4 dm³ = 0,714 mol/dm³.
pH = pKa + log (c(HNO₂) / c(NaNO₂)).
pH = 3,4 + log (0,714 mol/dm³ / 0,714 mol/dm³) = 3,4.
It has a 1:2 ratio
If you look at the start of PbO2 it does not have a number so that is the one and if you look at 2H2O that has a 2 in front so that is where you get the 1:2 ratio
The AZX symbol of a cation with 13 neutrons is A = 24 , Z = 11 and X = Na+
<h3>What is AZX?</h3>
AZX is a symbol which stands for;
- A is the mass number
- Z is the atomic number or the number of protons
- X is the chemical symbol of the element
Note, cations are positively-charged ions having more protons than electrons due to loss of one or more electrons.
Sodium ion represented as Na+ is a cation which lost one electron. It has 13 neutrons and 11 protons.
But the mass number of an element, A is the sum of protons and neutrons of the element.
Thus, for Na+
A = 13 + 11 = 24
Z = 11
X = Na+
Therefore, the AZX symbol of a cation with 13 neutrons is A = 24 , Z = 11 and X = Na+
Learn more about sodium ion here:
brainly.com/question/1933786
#SPJ1
X volume= 2x2x2=8
y volume= 8x8x8=512
512/8=64 so you can fit 64
They can both be converted to each other. Hopefully this helps! :)<span />
