<h2>5060 have three significant figures : Explanation given below </h2>
Explanation:
Significant figures
The significant figures (also known as the significant digits and decimal places) of a number are digits that possess certain meaning .
It includes all digits except: zeros
Rules to find significant figures
1.All non-zero digits are considered significant. For example, 23 has two significant figures.
2.Zeros in between two non-zero digits are significant: like in 202.1201 has seven significant figures.
3.Zeros to the left of the significant figures are not significant. For example, .000021 has two significant figures, zeros have no value .
4.Zeros to the right of the significant figures are significant.
That is the reason in number 5060 , it has 3 significant figures .
Alcohol is a pure substance
Answer is: D. Na2SO4.
b(solution) = 0.500 mol ÷ 2.0 L.
b(solution) = 0.250 mol/L.
b(solution) = 0.250 m; molality of the solutions.
ΔT = Kf · b(solution) · i.
Kf - the freezing point depression constant.
i - Van 't Hoff factor.
Dissociation of sodium sulfate in water: Na₂SO₄(aq) → 2Na⁺(aq) + SO₄²⁻(aq).
Sodium sulfate dissociates on sodium cations and sulfate anion, sodium sulfate has approximately i = 3.
Sodium chloride (NaCl) and potassium iodide (KI) have Van 't Hoff factor approximately i = 2.
Carbon dioxide (CO₂) has covalent bonds (i = 1, do not dissociate on ions).
Because molality and the freezing point depression constant are constant, greatest freezing point lowering is solution with highest Van 't Hoff factor.
We have been given the condition that carbon makes up 35%
of the mass of the substance and the rest is made up of oxygen. With this, it
can be concluded that 65% of the substance is made up of oxygen. If we let x be
the mass of oxygen in the substance, the operation that would best represent
the scenario is,
<span> x = (0.65)(5.5 g)</span>
<span> <em> </em><span><em>x =
3.575 g</em></span></span>
