Oh my i really hope no one from my school sees my comments
Answer is: volume of H₂SO₄ is 42.1 mL.<span>
Chemical reaction: H</span>₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O.<span>
c(H</span>₂SO₄) = 0,4567 M = 0,4567 mol/L.<span>
V(NaOH) = 30 mL </span>÷ 1000 mL/L <span>= 0,03 L.
c(NaOH) = 0,321 M = 0,321 mol/L.
n(NaOH) = c(NaOH) · V(NaOH).
n(NaOH) = 0,321 mol/L · 0,030 L.
n(NaOH) = 0,00963 mol.
From chemical reaction: n(H</span>₂SO₄) : n(NaOH) = 1 : 2.<span>
n(H</span>₂SO₄) = 0,01926 mol.<span>
V(H</span>₂SO₄) = n(H₂SO₄) ÷ c(H₂SO₄).<span>
V(H</span>₂SO₄) = 0,01926 mol ÷ 0,4567 mol/L.<span>
V(H</span>₂SO₄<span>) = 0,0421 L = 42,1 mL.</span>
The correct answer is
D burning wood
because it's changing the wood.
The other's are physical changes because it's still the same thing, it's just in a different form.
Glad I could help, and good luck!
AnonymousGiantsFan
This is a redox reaction.
3Fe + 2O₂ → Fe₃O₄ (Fe⁺²O·Fe⁺³₂O₃)
Fe - 2e⁻ = Fe⁺²
Fe - 3e⁻ = Fe⁺³
O₂ + 4e⁻ = 2O⁻²
