Question

1.According to your group data, how does NaCl and/or water intake influence urine production?

These are the data:

we explore how consuming various amounts of water and electrolytes cause changes in urine volume produced, urine sodium concentration, and urine osmolarity. In the following groups, urine is collected at 30 minute intervals: In response to drinking 1L of water. In response to eating pretzels containing 1g of NaCl. In response to drinking 1L of water and eating pretzels containing 1g of NaCl.

2. Explain the relation between osmolarity and sodium chloride concentration.

3. Predict the osmolarity of a 0.05 M solution of MgCl2.

Answer 1

1st part-

high intake of NaCl will increase the amount of salt in blood. High concentration of salt in blood will affect the kidney's filtration process. As there is more salt, more water will be absorbed from the renal tubules in order to maintain osmolarity of blood. This will cause fluid retention in body and less urine will be produced. Also produced urine will be more concentrated.

When water intake is increased, it will lead to more production of urine and diluted urine is excreted. High water intake will cause increase frequency of voiding and will reduce the osmolality of blood..

2nd part-

osmolarity is determined by the total number of ions present. Higher the number of the free ions in the solution, higher will be the osmolarity. NaCl dissociate in water to form sodium and chloride ion and thus increases osmolarity. Higher the amount of NaCl added, higer is the osmolarity. Thus osmolarity and NaCl concentration are directly proportional.

3rd part-

MgCl2 after dissociation gives one magnesium ion and two chloride ion

Total 3 ions

Molarity of MgCl2 = 0.05

So osmolarity of the solution = molarity × number of ions

= 0.05 × 3

= 0.15 osmol