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Questions in chemistry

[Answered] To prepare 9,10-anthraquinone from benzene via benzoylbenzoic acid.

[Answered] Choose the products that complete the reaction. The chemical equation may not be balanced. [tex]Al+H_2 SO_4 \rightarrow ?[/tex] A. [tex]Al _2(SO _4)_3+ H _2 O[/tex] B. [tex]Al _2(SO _4)_3+ CO _2+ H _2 O[/tex] C. [tex]Al _2(SO _4)_3+ H _2[/tex]

[Answered] What is the pH of a solution with [H+] = [tex]$7.0 \times 10^{-2}$[/tex] ? A. -0.85 B. -1.15 C. 1.15 D. 0.85

[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] (a) State two differences between a physical change and a chemical change. (b) Complete the table by giving the name of the process of change and the type of change, 'chemical' or 'physical'. | Change | Name of Process | Is it Physical or Chemical Change? | |---|---|---| | (i) Dry carbon dioxide changes into vapour | | | | (ii) Burning of magnesium in the air | | | | (iii) Sugar added into a beaker of water | | | | (iv) Sugar gives rise to carbon and water vapour upon heating | | | | (v) Burning a piece of paper | | |

[Answered] Which statement best describes the formula equation [tex]Cl _2(g)+2 KBr ( aq ) \rightarrow 2 KCl ( aq )+ Br _2( I )[/tex] ? A. Carbon iodide reacts with potassium bromide to form potassium carbon iodide and bromine. B. Bromine gas reacts with a solution of potassium chloride to form potassium bromide and chlorine gas. C. Potassium bromine gas reacts with liquid chlorine to form potassium chloride in solution and bromine gas. D. Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.

[Answered] Hydrogen has three isotopes ¹H, ²H, and ³H. What is the difference between these three isotopes? A. The number of protons ranges from 1 to 3. B. The number of electrons ranges from 1 to 3. C. The number of neutrons ranges from 0 to 2. D. The number of protons ranges from 0 to 2.

[Answered] What is the pH of a 0.048 M solution of hydrochloric acid ([tex]H^+[/tex])? A. 0.32 B. 4.80 C. -0.758 D. none of these available choices E. 1.32

[Answered] Choose the products that complete the reaction. The chemical equation may not be balanced. [tex]HC _2 H _3 O _2+ Ca ( OH )_2 \rightarrow[/tex] ? A. [tex]Ca \left( C _2 H _3 O _2\right)_2+ H _2 O[/tex] B. [tex]Ca \left( C _2 H _3 O _2\right)_2+ CO _2+ H _2 O[/tex] C. [tex]Ca \left( C _2 H _3 O _2\right)_2+ H _2[/tex]

[Answered] Consider the chemical equation in equilibrium: [tex]CH_4(g)+H_2 O(g) \Leftrightarrow CO(g)+3 H_2(g)[/tex] What will happen to the equilibrium of this reaction if the pressure is increased? A. The equilibrium will shift to the left to favor the reverse reaction. B. The equilibrium will not be affected by changing the pressure. C. The equilibrium will not be reestablished after this kind of stress.