Creatinine, , is a by-product of muscle metabolism, and creatinine levels in the body are known to be a fairly reliable indicator of kidney function. The normal level of creatinine in the blood for adults is approximately 1.0 mg per deciliter (dl) of blood. If the density of blood is 1.025 g/ml, calculate the molality of a normal creatinine level in a 10.0-ml blood sample.

Molality = 0.0862 mole/kg

Explanation:

Molality = (number of moles of solute)/(mass of solvent in kg)

Number of moles of solute = (mass of Creatinine in the blood sample)/(Molar mass of Creatinine)

To obtain the mass of creatinine in 10 mL of blood. We're told that 1 mg of Creatinine is contained in 1 decilitre of blood.

1 decilitre = 100 mL

1 mg of Creatinine is contained in 100 mL of blood

x mg of Creatinine is contained in 10 mL of blood.

x = (1×10/100) = 0.1 mg = 0.0001 g

Molar mass of Creatinine (C₄H₇N₃O) = 113.12 g/mol

Number of moles of Creatinine in the 10 mL blood sample = (0.0001/113.12) = 0.000000884 moles

Mass of 10 mL of blood = density × volume = 1.025 × 10 = 10.25 mg = 0.01025 g = 0.00001025 kg

Molality of normal creatinine level in a 10.0-ml blood sample = (0.000000884/0.00001025)

Molality = 0.0862 moles of Creatinine per kg of blood.

Hope this Helps!!!

pure water does not conduct electricity very well. however, when certain substances are dissolved in water, the solution does conduct electricity. you can make a simple device that shows how well a solution conducts electricity. this device uses a flashlight bulb to indicate how well the solution conducts electricity. the better the solution conducts electricity, the brighter the bulb will glow.

explanation:

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."