Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
Ecologists use food web diagrams as tools in their studies of different populations of organisms within an ecosystem because it shows the feeding relationship between organisms in the ecosystem.
<h3>What is a Food web?</h3>
This is defined as the graphical representation of the feeding relationship which occurs between organisms in the ecosystem and helps to predict the outcome in the addition or removal of a species.
The food web also helps to determine the various ways in which energy flows and it usually starts from the producers which are the plants as a result of their photosynthetic ability which involves the conversion of solar energy to chemical energy.
There are various organisms in the ecosystem and the food web helps to provide a better understanding of their feeding habits and impact various factors will result in.
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The answer is- Mass of flask = 608.04 g
Density (d) is defined as mass of substance divided by its volume. Thus, if mass and density are known, then Volume can be determined.
What is the formula of mass in terms of density?
- Let mass of substance be 'm' and volume be 'V'. Thus, as per the definition of density, it is expressed as-

Thus, mass can be expressed as-

- Now, mass of empty flask = 241.3 g and the mass of (flask + Water) = 489.1 g.
Thus, mass of water =
.
- Thus, mass of water = 247.8 g and density of water =
. Its volume is calculated as-

- Volume of flask = 247.8
. - Then when this flask is filled with chloroform (d =
), the mass of chloroform is-

- Hence, the mass of flask becomes =

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The mass of the aqueous solution in grams is obtained by subtracting mass of the 10.0 mL graduated cylinder alone from the mass of the cylinder + solution. Therefore mass of the solution is 2.951 g.
We have from the question, the following information;
Mass of empty 10.0 mL graduated cylinder to be 23.099 g
Mass of 10.0 mL graduated cylinder + 3.09 mL of solution to be 26.050g
Mass of aqueous solution in grams = mass of the cylinder + solution - mass of the 10.0 mL graduated cylinder alone
= 26.050g - 23.099 g
= 2.951 g
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