<span>The appropriate response is filtration. Filtration is any of different mechanical, physical or organic operations that different solids from liquids by including a medium through which just the liquid can pass. The liquid that goes through is known as the filtrate</span>
Answer:
3) NaCl.
Explanation:
<em>∵ ΔTf = iKf.m</em>
where, <em>i</em> is the van 't Hoff factor.
<em>Kf </em>is the molal depression freezing constant.
<em>m</em> is the molality of the solute.
<em>The van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass. </em>
<em></em>
- For most non-electrolytes dissolved in water, the van 't Hoff factor is essentially 1.
<em>So, for sugar: i = 1.</em>
<em>∴ ΔTf for sugar = iKf.m = (1)(Kf)(2.0 m) = 2 Kf.</em>
<em></em>
- For most ionic compounds dissolved in water, the van 't Hoff factor is equal to the number of discrete ions in a formula unit of the substance.
For NaCl, it is electrolyte compound which dissociates to Na⁺ and Cl⁻.
<em>So, i for NaCl = 2.</em>
<em>∴ ΔTf for NaCl = iKf.m = (2)(Kf)(1.0 m) = 2 Kf.</em>
<em></em>
<em>So, the right choice is: 3) NaCl.</em>
<em></em>
Mass of this substance = 9.928 g
<h3>Further explanation</h3>
Molarity is a way to express the concentration of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
So to find the number of moles can be expressed as
mol of substance -Lithium nitrite - LiNO₂ :
V = 250 ml = 0.25 L
M = 0.75 M
So mass of this substance - LiNO₂ (MW=52,947 g/mol) :
Answer:
B. use a new pair of gloves for each piece of evidence
Explanation:
When it comes to the basic precautions of handling biological evidence samples, one has to prevent cross contamination. This refers to the<em> transfer of DNA from one evidence to another evidence</em>; thus, it is important for Jane to use a new pair of gloves for each piece of evidence in order to prevent such occurrence.
Wearing of gloves will also <em>prevent Jane's DNA from being implanted into the sample</em>, and it will keep her safe from contracting blood-borne pathogens like those in the saliva, blood or semen.
