How many lone pairs must an atom possess to have trigonal pyramidal molecular structure? Select the correct answer below: l 2 3

Which statement would be the most useful for deriving the ideal I gas law? Volume is directly proportional to the number of moles. Volume is inversely proportional to the temperature. Pressure is directly proportional to the volume. Pressure is inversely proportional to the number of moles.

Hydrogen sulfide is: A) Odorless B) Colorless C) Not flammable D) Red in color

Question 18 of 20 What is the name for $Mg_{3}N_{2}$ A. Magnesium nitride B. Magnesium dinitride C. Trimagnesium dinitride D. Dimagnesium trinitride

Give the IUPAC name for the organic compound shown: $CH_{3}-CH-CH-CH_{2}-COOH$ chloro-isopropyl alcohol 3-chloropentanoic acid 3-chloropentanone 2-chloropentanal

Question 21 Calculate $\Delta _{r}G^{\circ }$ at $25.0^{\circ }C$ for the reaction below. $2Na(s)+2H_{2}O(l)\rightarrow 2NaOH(aq)+H_{2}(g)$ Given: $\Delta _{r}H^{\circ }=-314kJ$ and $\Delta _{r}S^{\circ }=-117J/K$ (Report your answer in units of kJ, to one decimal place, i.e xxx.x, and no units are necessary in the answer.) (Remember to include a negative sign, if necessary.)

What approximate carburization time is needed to achieve $5\% $ atomic carbon at a distance from the surface of 0.4 microns? 1 hour 1.5 hours 2 hours 2.5 hours

Which type of reaction is represented by the generic equation $AB+CD\rightarrow AD+CB$ combustion decomposition single replacement double replacement

Given the equilibrium constants for the following reactions: $4Cu(s)+O_{2}(g)\rightleftharpoons 2Cu_{2}O(s),K_{1}=6.19$ $4CuO(s)\rightleftharpoons 2Cu_{2}O(s)+O_{2}(g),K_{2}=0.16$ what is K for the system $2Cu(s)+O_{2}(g)\rightleftharpoons 2CuO(s)$ equivalent to? (Report your answer to four decimal places, i.e.xxxx) $\square $

What is the pH of a solution made by combining 0.484 m $NaC_{2}H_{3}O_{2}$ with 0.042 M $HC_{2}H_{3}O_{2}$ ? The $K_{a}$ of acetic acid is $1.75\times 10^{-5}$ (Report your answer to three decimal places, i.e x.xxx)

As pure molecular solids , identify the types of intermolecular forces in each: $PH_{3}$ $\square $ HF $\square $ $CO_{2}$ $\square $