12. 632 g margansovka qizdirilganda \( 33,6 / \) (n.sh da) \( \mathrm{O}_{2} \) hosil bo'lsa, margansovka tarkibidagi sof moddaning massa ulushini hisoblang \( \begin{array}{llll}\text { A) } 0,65 & \text { B) } 0,70 & \text { C) } 0,75 & \text { D) } 0,85\end{array} \)

possible Find the hydrogen ion concentration of a solution whose pH is 7.1 . Use the formula \( \mathrm{pH}=-\log \left[\mathrm{H}^{+}\right] \)

5) \( \mathrm{Ag}_{2} \mathrm{O} \rightarrow \)

10 Essay 5 points Please identify the following components for the element Selenium: 1 Chemical Symbol 2. Atomic Number 3. Family \# 4. Valence Electrons 5. Category Edit View Insert Format Tools Table

14 Nitrogen has atomic number 7 and oxygen has atomic number 8 What is total number of electrons in \( \left(\mathrm{NO}_{3}\right)^{-} \)ion ? \( \begin{array}{ll}\text { (a) } 15 \mathrm{e}^{-} & \text {(b) } 31 \mathrm{e}^{-} \\ \text {(c) } 32 \mathrm{e}^{-} & \text {(d) } 46 \mathrm{e}^{-}\end{array} \)

6. If 380 g of cottonseed oil measures 415 mL , what is its specific gravity? 7. If \( 2 \mathrm{fl} \). oz. of glycerol weighs 74.1 g , what is its specific gravity? 8. Five pints of diluted hydrochloric acid weights 2.79 kg . Calculate its specific gravity.