ITS HYDROGEN IONS CONCERNTATION IS MORE BECAUSE ON THE LEFT SIDE OF PH SCALE THERE IS INCREASING OF H+ IONS AND PH IS LESS THAN 7 IS MORE ACIDIC IN NATURE
You first need to write the balanced chemical reaction for what is going on.
Ca(OH)₂+2HCl→2H₂O+CaCl₂
After you make the balanced chemical reaction, First you find the moles of HCl used. To do this multiply 0.0375L by 0.124M to get 0.00465mol HCl. Then you multiply 0.00465mol HCl by (1mol Ca(OH)₂)/(2mol HCl) to get 0.002325mol Ca(OH)₂. Finally to find concentration of Ca(OH)₂ used you divide 0.002325mol by 0.020L to get 0.116M Ca(OH)₂.
Therefore the concentration of the unknown solution of Ca(OH)₂ was 0.116M.
I hope this helps. Let me know if anything is unclear.
Answer: pretty sure it is D
Answer is: Proteins-growth and repair of cellular structures.
Proteins are macromolecules made of amino acids (usually 20 amino acids) and they are main structure molecules of all living cells.
Lipids and sugars (glucose) are main source of energy in every living organism and they are used as the cell's energy reserves.