Answer:
3.9%
Explanation:
Exact melting point = 123°C
Measured melting point = 128°C
% error; |measured - exact|/exact × 100
% error = |123 -128|/128 × 100
%error = 3.9%
Percentage error in temperature measurement = 3.9 %
Answer:
455.4 g
Explanation:
Data given:
no. of moles of (NH₄)₂SO₄= 3.45 mol
mass of (NH₄)₂SO₄ = ?
Solution
Formula will be used
no.of moles = mass in grams / molar mass
Rearrange the above equation for mass
mass in grams = no. of moles x molar mass . . . . . . . . (1)
molar mass of (NH₄)₂SO₄
molar mass of (NH₄)₂SO₄ = 2(14 + 4(1)) + 32 + 4(16)
molar mass of (NH₄)₂SO₄ = 2 (14 +4) + 32 + 64
molar mass of (NH₄)₂SO₄ = 2 (18) + 32 + 64
molar mass of (NH₄)₂SO₄ = 36 + 32 + 64 = 132 g/mol
Put values in equation 1
mass in grams = 3.45 mole x 132 g/mol
mass in grams = 455.4 g
So,
mass of (NH₄)₂SO₄ = 455.4 g
Answer:
2.08 moles
Explanation:
number of molecules = mass / molecular mass of SO₄
number of molecules = 200 g / 96.06 g/mol
number of molecules ≈ 2.08
The answer is B. I just took the quiz and got it right. Hope it's the same thing for you.
