Answer:Water contains almost one thousand times more matter than the same volume of air would, therefore it is denser. ... If 500 mL of a liquid has a density of 1.11 g/mL, what is its mass? ... Density is the mass per unit of volume of a substance. ... A block of platinum with a mass of 4,290 kilograms has a volume of .2 cubic meters.
Explanation:
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Compounds Na₂SO₄ and NaCl are mixed together are we are asked to find the concentration of Na⁺ in the mixture
Na₂SO₄ ---> 2 Na⁺ + SO₄³⁻
1 mol of Na₂SO₄ gives out 2 mol of Na⁺ ions
the number of Na₂SO₄ moles added - 0.800 M/1000 * 100 ml
= 0.08 mol
therefore number of Na⁺ ions from Na₂SO₄ = 0.08 * 2 = 0.16 mol
NaCl ----> Na⁺ + Cl⁻
1 mol of NaCl gives 1 mol of Na⁺ ions
number of NaCl moles added = 1.20 M/1000 * 200 ml
= 0.24 mol
number of Na⁺ ions from NaCl = 0.24 mol
total number of Na⁺ ions in the mixture = 0.16 mol + 0.24 mol = 0.4 mol
as stated the volumes are additive,
therefore total volume = 100 ml + 200 ml = 300 ml
the concentration of Na⁺ ions = number of moles / volume
= 0.4 mol/ 0.3 dm³
concentration of Na⁺ = 1.33 mol/dm³
Answer:
CaCl₂ > CH₃OH = LiCl > C₆H₁₂O₆
Explanation:
The osmotic pressure of a compound is calculated using the following expression:
π = MRT (1)
This expression is used when the substance is nonelectrolyte. If the solution is electrolyte solution then we need to count the van't hoff factor into the expression so:
π = MRTi (2)
Now, we have 4 solutions here, only two of them are electrolyte solution, this means that these solutions can be dissociated into separate ions. These solutions are LiCl and CaCl₂. It can be shown in the following reactions:
LiCl -------> Li⁺ + Cl⁻ 2 ions (i = 2)
CaCl₂ ---------> Ca²⁺ + 2Cl⁻ 3 ions (i = 3)
The methanol (CH₃OH) and glucose (C₆H₁₂O₆) are non electrolyte solutions, therefore they are not dissociated. So, let's use expression (1) for methanol and glucose, and expression (2) for the salts:
CaCl₂: π = 1 * 3 * RT = 3RT
CH₃OH: π = 2 * RT = 2RT
C₆H₁₂O₆: π = 1 * RT = 1RT
LiCl: π = 1 * 2 * RT = 2RT
Finally with these results we can conclude that the decreasing order of these solutions according to their osmotic pressures are:
<h2>
CaCl₂ > CH₃OH = LiCl > C₆H₁₂O₆</h2>
