The number 90 has 1 sig fig.
If concentration of HCl is 1 mol/dm³ :
m(<span>erlenmeyer flask) = 88,00 g.
m(Zn) = 25,0 g.
V(HCl) = 15 ml = 15 cm</span>³ = 0,015 dm³.
Chemical reaction: Zn + 2HCl → ZnCl₂ + H₂.
n(HCl) = c(HCl) · V(HCl).
n(HCl) = 1 mol/dm³ · 0,015 dm³ = 0,015 dm³.
n(Zn) = 25 g ÷ 65,4 g/mol = 0,38 mol.
n(H₂) = 0,015 mol ÷ 2 = 0,0075 mol.
m(H₂) = 0,0075 mol · 2g/mol = 0,015 g.
Answer:
Al4C3 + 12H2O = 3CH4 + 4Al(OH)3
Explanation:
Not sure if any explanation is needed but always start with the most complex compound. In this case it is Al(OH)3. You can see that there is 4 Aluminiums on the other side so I would start by putting a 4 next to the Al(OH)3. This now gives me 12 Hydrogens and 12 Oxygens on the right side. I put a 3 next to the CH4 to balance the Carbons on the left side. This leaves me with 12 Oxygens and 24 Hydrogens on the right side. This ends up being perfect because I can put a 12 next to the H2O.
Answer:
D. has characteristics between conductor and insulator
Answer:
1.64 moles O₂
Explanation:
Part A:
Remember 1 mole of particles = 6.02 x 10²³ particles
So, the question becomes, how many '6.02 x 10²³'s are there in 9.88 x 10²³ molecules of O₂?
This implies a division of given number of particles by 6.02 x 10²³ particles/mole.
∴moles O₂ = 9.88 x 10²³ molecules O₂ / 6.02 x 10²³ molecules O₂ · mole⁻¹ = 1.64 mole O₂
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Part B needs an equation (usually a combustion of a hydrocarbon).