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Questions in chemistry

[Done] 0.083 mole of carbohydrate with empirical formula CH₂O contains 1 g of hydrogen. What is the molecular formula of the carbohydrate? Options: (1) C₅H₁₀O₅ (2) C₆H₁₂O₆ (3) C₁₂H₂₂O₁₁ (4) C₆H₁₂O₄

[Done] Which best describes a neutralization reaction? A. a reaction between an acid and a base B. a reaction between two acids C. a reaction between a base and a salt D. a reaction between two salts

[Done] Select the correct answer. Thomas has [tex]$235$[/tex] grams of [tex]$K_2S$[/tex] in the chemistry lab. How many atoms of potassium (K) are in [tex]$235$[/tex] grams of the compound? A. [tex]$2.13 \times 10^{23}$[/tex] B. [tex]$4.26 \times 10^{23}$[/tex] C. [tex]$2.57 \times 10^{24}$[/tex] D. [tex]$3.37 \times 10^{24}$[/tex] E. [tex]$7.08 \times 10^{24}$[/tex]

[Done] In a school's laboratory, students require 50.0 mL of [tex]$2.50 M H _2 SO _4$[/tex] for an experiment, but the only available stock solution of the acid has a concentration of 18.0 M. What volume of the stock solution would they use to make the required solution? Use [tex]$M_i V_i=M_i V_r$[/tex]. A. 0.900 mL B. 1.11 mL C. 6.94 mL D. 7.20 mL

[Done] Which statement accurately describes the chemical symbol of an element? A. The chemical symbol is always a single letter. B. The chemical symbol always starts with the same letter as the name of the element. C. The chemical symbol always begins with a capital letter. D. The chemical symbol can be shared by more than one element.

[Done] Balance these redox reactions by the oxidation number method. [tex]MnO₄⁻ + I⁻⁷ \rightarrow MnO₂ + I₂[/tex]

[Done] Choose the products that complete the reaction. The chemical equation may not be balanced. [tex]$NaHCO _3+ HC _2 H _3 O _2 \rightarrow$[/tex] ? A. [tex]$NaC _2 H _3 O _2+ H _2 O$[/tex] B. [tex]$NaC _2 H _3 O _2+ CO _2+ H _2 O$[/tex] C. [tex]$NaC _2 H _3 O _2+ H _2$[/tex]

[Done] A chemistry teacher adds 50.0 mL of $1.50 M H _2 SO _4$ solution to 200 mL of water. What is the concentration of the final solution? Use $M_i V_i=M_i V_{\text {T }}$. A. 0.300 M B. 0.375 M C. 6.00 M D. 7.50 M

[Done] Consider the half reactions below for a chemical reaction. [tex]\begin{array}{l} Mg \longrightarrow Mg^{2+}(aq)+2 e^{-} \\ 2 H^{+}(aq)+2 e^{-} \longrightarrow H_2(g) \end{array}[/tex] What is the overall equation for this chemical reaction? A. [tex]Mg ( s )+2 H ^{+}( aq ) \longrightarrow Mg ^{2+}( aq )+ H _2(g)[/tex] B. [tex]Mg ( s )+2 H ^{+}( aq ) \longrightarrow Mg ^{2+}( aq )+2 e ^{-}[/tex] C. [tex]Mg ^{2+}( aq )+ H _2(g) \longrightarrow Mg ( s )+2 H ^{+}( aq )[/tex] D. [tex]Mg ( s )+2 H \longrightarrow Mg ( aq )+ H _2(g)[/tex]

[Done] A certain buffer solution contains equal concentrations of X⁻ and HX. The K_b for X⁻ is 10⁻¹⁰. The pH of the buffer is: 1) 4 2) 7 3) 10 4) 14