Answer:
The mass ratio of zinc to sulfide is 85:42.
2.5559 kg of Zn are in 3.82 kg of ZnS.
Explanation:
a) Mass of zinc sulfide = 254 g
Mass of zinc in a zinc sulfide sample = 170 g
Mass of sulfide in zinc sulfide sample = x
254 g = 170 g+ x
x = 84 g
The mass ratio of zinc to sulfide:
b) Mass of zincsulfide sample = 3.83 kg
The mass ratio of zinc to sulfide is 85:42.
Let the mass of zinc and sulfide be 85x and 42x respectively:
85 x+ 42 x=3.82 kg
x =0.03007 kg
Mass of an zinc= 85x=85 × 0.03007 kg= 2.5559 kg
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>
Answer:
The correct answer is 1 millon years.
Explanation:
Fossil rocks serve to study the evolution of species throughout history. Species usually adapt to survive the changing environment around them. Given this fact, we can deduce that the oldest species were very different from the way they are today. This means that the current species are more similar to those that preceded them more recently. The fossil of 1 million years ago is the most similar to today's horse.
Have a nice day!
The molecular formula of the liquid : C₆H₁₂
<h3>Further explanation</h3>
Given
molar ratio C H = 1.2 : 0.12
0.12 g at STP gave 32 cm³(0.032 L)
Required
The molecular formula
Solution
At STP, 1 mol = 22.4 L, so for 0.032 L :
mol = 0.032 : 22.4
mol = 0.00143
Molar mass (M) of liquid :
M = mass : mol
M = 0.12 g : 0.00143 mol
M = 83.92≈84 g/mol
C : H = 1 : 2
(CH₂)n=84
(12+2.1)n=84
(14)n=84
n=6
(CH₂)₆=C₆H₁₂
