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Questions in chemistry

[Answered] Which formula equation shows a reversible reaction? [tex]2 Na + F _2 \rightarrow 2 NaF[/tex] [tex]CaCO _3 \rightarrow CaO + CO _2[/tex] [tex]NH _4 Cl ( s ) \leftrightarrow NH _3(g)+ HCl ( g )[/tex] [tex]2 H _2 O _2( aq ) \xrightarrow{ Br } 2 H _2 O ( l )+ O _2(g)[/tex]

[Answered] Type the correct answer in the box. Some fertilizer blends contain magnesium nitrate $\left( Mg _{\left( NO _3\right)_2}\right)$. Suppose that a chemist has 1.24 liters of a 2.13 M solution of magnesium nitrate. If the chemist dilutes the solution to 1.60 M, what is the volume of the new solution? Express your answer to three significant figures. The volume of the new solution is $\square$ liters.

[Answered] Find the number of molecules that are planar: (i) SF₄ (ii) XeF₆ (iii) XeF₂ (iv) XeF₄ (v) H₂O (vi) NH₃ (vii) PH₃ (viii) PCl₅ (ix) PCl₃

[Answered] What is the formula equation for the reaction between sulfuric acid and dissolved sodium hydroxide if all products and reactants are in the aqueous or liquid phase? [tex]$HCl ( aq )+ NaOH ( aq ) \rightarrow NaCl ( s )+ H _2 O ( l )$[/tex] [tex]$H _2 SO _4( aq )+ Ca ( OH )_2( aq ) \rightarrow CaSO _4( aq )+2 H _2 O ( l )$[/tex] [tex]$H _2 SO _4( aq )+2 NaOH ( aq ) \rightarrow Na _2 SO _4( aq )+2 H _2 O ( l )$[/tex] [tex]$2 H _3 PO _4( aq )+3 Ca ( OH )_2( aq ) \rightarrow Ca _3\left( PO _4\right)( s )+6 H _2 O ( l )$[/tex]

[Answered] Which best describes the pH scale? A. Acids measure below 7. B. Bases measure below 7. C. Acids and bases measure above 7. D. Bases and acids measure at 7.

[Answered] What compound is now used as the primary replacement for CFCs? A. methyl chloroform B. carbon tetrachloride C. methyl bromide D. hydrofluorocarbon

[Answered] i. Describe how sulphur (VI) oxide (SO3) is converted to sulphuric acid during the process. ii. State two disadvantages of having sulphur dioxide (SO2) in the environment.

[Answered] Phthalonitrile $\left( C _8 H _4 N_2\right)$ is produced by the ammoxidation of o-xylene ( $C _8 H _{10}$ ) according to the following reaction: $C_8 H_{10}(l)+O_2(g)+NH_3(g) \rightarrow C_8 H_4 N_2(s)+H_2 O(l)$ How many grams of water would be produced by the complete ammoxidation of 3.98 moles of oxylene?

[Answered] Which is a way to express the concentration of a solution? A. parts per billion B. moles C. molar mass D. force per square meter

[Answered] Part D. The two elements predicted by Mendeleev were discovered later. Locate the elements gallium (Ga) and germanium (Ge) in the periodic table. Click each element to reveal its properties. Explain how these elements fit Mendeleev's predictions.