The correct answer is C)
How can we solve this question?
Ringer liquid is a physiological solution used to keep isolated animal organs alive. It contains the following ions in the indicated concentrations:
What salts must be dissolved in the water?
A) CaCl2 ; KCl ; NaC3H5O3
B) NaCl ; KCl ; Ca(C3H5O3)2
C) NaCl ; CaCl2 ; KCl ; NaC3H5O3
D ) NaCl ; CaCl2 ; KCl ; KC3H5O3
We must know where these ions mostly concentrated relative to a living cell.
Normally concentration of Na+ and Cl- are high and concentration of K+ and Ca2+ is low in the extracellular milieu/matrix (ECM) relative to the inside of the cell (ICM). Lactate (C3H5O3-)concentration must be minimal in both ECM and ICM under normal non-stranous conditios.
Our cells must survive in the Ringer liquid milieu which will be our ECM.
Knowing and comparing this with the number of moles we get by dissolving these salt series in water to make Ringer liquid, shows us which series follow the recommended concentrations.
We can see, the series in C with minimal [Ca2+], [K+],[lactate] and maximal [Na+],[Cl-] is the only option which can fulfill the demand for all ions at the same time.