Calcium carbonate has the formula \( \mathrm{CaCO}_{3} \). a What is its relative formula mass \( \left(M_{\mathrm{r}}\right) \) ? \( \left(A_{\mathrm{r}}: \mathrm{Ca}=40, \mathrm{C}=12, \mathrm{O}=16\right) \) b If 100 g of calcium carbonate contain 40 g of calcium, how much calcium is present in 15 g of calcium carbonate?

The pH value is an expression of the molarity of \( \mathrm{H}_{3} \mathrm{O}^{+} \)ions in solution. This concentration has strong impact on chemical reactions. The molarity is very small value, and therefore awkward to use. The pH scale simplifies this concentration making communication easier and faster. Demonstrate the relationship between pH and \( \mathrm{H}_{3} \mathrm{O}^{+} \)molarity, using the formula, \( \mathrm{pH}=-\log \left(\mathrm{H}_{3} \mathrm{O}^{+}\right) \) where () indicates concentration in molarity of a substance. What is the pH of a solution, having the \( \mathrm{H}_{3} \mathrm{O}^{+} \)concentration of 0.000491 M ? Add your answer

Homework Questions Content Question 1 Using principles of molecular orbital theory, how many unpaired electrons are in each of the following molecules? NO \( { }^{+} \)Blank 1 NO Blank 2 BC Blank 3 BeC Blank 4

3. จงอ่านชื่อของสารประกอบต่อไปนี้ 3.1 Bas

A substance with a pH of 2 is

1. Considere la evaporación de agua liquida para formar vapor a 1 atm de presion. a) ¿Est proceso es endotérrico oxotêrmico? b) ¿En cué intervalo de temperatura el proceso es espontaneo c) ¿En qué intervalo de temperatura es un proceso no espontàneo? d) ¿A qué temperaura las dos fases estàn en equilibrio?