The percent by mass of Ca in CaCl2 is equal to 1. (40/111) x 100
2. (111/40) x 100
3. (3/1) x 100
4. (1/3) x 100

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

What is the work done by the electric force to move a 1 c charge from a to b?

Suppose you discovered a new element with 120 protons and 2 electrons in its outer level . i'm what group does this new element belong? what properties would you expect it to have