VincenTragosta - Tanya, Jawab, dan Belajar Tanpa Batas Logo

Questions in chemistry

[Terjawab] Why study chemistry? a) to be better informed about the world b) to be better able to make informed decisions c) to learn a technique for identifying and solving problems d) all of the above

[Terjawab] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Terjawab] Fill in the gaps to balance the equation. Use the smallest set of whole numbers to balance the equation and include coefficients of "1" when appropriate. [tex]$\square$ Ca ( OH )_2+ $\square$ CuI _2 \rightarrow $\square$ CaI _2+ $\square$ Cu ( OH )_2[/tex] Complete the table to determine how many atoms of each element are present in the reactants and products. | Element | Reactant | Products | | :------ | :------- | :------- | | Ca | $\square$ | $\square$ | | O | $\square$ | $\square$ | | H | $\square$ | $\square$ | | Cu | $\square$ | $\square$ | | I | $\square$ | $\square$ |

[Terjawab] Which of the following is an unsaturated hydrocarbon? A. Butene B. Ethane C. Heptane D. Hexane E. Methane

[Terjawab] Calculate the enthalpy change (kJ) when 40.0 g of [tex]$Na_2 O_2$[/tex] reacts with excess water? Report your answer with the correct number of significant figures. Do not include units in your answer.

[Terjawab] Translate the following statements into chemical equations and then balance them: a. Hydrogen combines with nitrogen to form ammonia. b. Hydrogen sulphide burns in air to give water and sulphur dioxide. c. Zinc reacts with dilute sulphuric acid to give zinc sulphate and hydrogen. d. Potassium metal reacts with water to give potassium hydroxide and hydrogen.

[Terjawab] Under which conditions would the solubility of a gas be greatest? A. high pressure and high temperature B. high pressure and low temperature C. low pressure and high temperature D. low pressure and low temperature

[Terjawab] What is the formula for the ammonium ion? [tex]NH _4{}^{+}[/tex]

[Terjawab] Given the following reaction, what will cause no impact on the equilibrium if the forward reaction is endothermic? [tex]2 PbS(s)+3 O_2(g)+C(s) \rightleftharpoons 2 Pb(s)+CO_2(g)+2 SO_2(g)[/tex] A. adding C B. adding Pb C. applying pressure D. applying heat

[Terjawab] {\begin{tabular}{|c|c|} \hline liquid & density \ \hline glycerol & $1.3 g \cdot mL ^{-1}$ \ \hline dimethyl sulfoxide & $1.1 g \cdot mL ^{-1}$ \ \hline acetone & $0.79 g \cdot mL ^{-1}$ \ \hline methyl acetate & $0.93 g \cdot mL ^{-1}$ \ \hline ethanolamine & $1.0 g \cdot mL ^{-1}$ \ \hline \end{tabular}} Next, the chemist measures the volume of the unknown liquid as $1574 . cm ^3$ and the mass of the unknown liquid as {\begin{tabular}{|l|l|} \hline Calculate the density of the liquid. Round your answer to 3 significant digits. & $\square$ $g \cdot mL ^{-1}$ \ \hline Given the data above, is it possible to identify the liquid? & yes no \ \hline If it is possible to identify the liquid, do so. & glycerol dimethyl sulfoxide acetone methyl acetate ethanolamine \ \hline \end{tabular}}