When products form in an exergonic reaction, the <span>energy required to break bonds is less than the energy released from new bonds. This is usually given off as light. I hope this is the answer you are looking for. Looking forward to help you again. Have a great day ahead!</span>
Molarity is the number of moles of solute in 1 L of solution
molarity of KBr solution is 0.630 M
this means that there there are 0.630 moles of KBr in 1 L solution
then in 615 mL number of KBr moles are - 0.630 mol/L x 0.615 L = 0.387 mol
mass of KBr is - molar mass x number of moles
KBr molar mass is 119 g/mol x 0.387 mol = 46.1 g
mass of KBr is 46.1 g
B.
(2.43*10^24)*1/(6.022*10^23)