IdeasCuriosas - Every Question Deserves an Answer Logo

Questions in chemistry

[Answered] Which of these is an example of a chemical property? A. Sodium oxidizes in air. B. Table salt is a white crystal. C. Sodium metal boils at 883 °C.

[Answered] Draw the Lewis structure for ethylamine $(C_2H_7N)$. Ethylamine molecules have one amino group. Be certain you include any lone pairs.

[Answered] What is the formula of aluminum acetate? $\left( C _2 H _3 O _2\right)_3 Al$ AIAc $AlC _2 H _3 O _{23}$ $Al \left( C _2 H _3 O _2\right)_3$

[Answered] Which polyatomic ion has a carbon atom, 3 oxygen atoms and a -2 charge? A. carbocation B. carbide C. carbonate D. carbonite

[Answered] What is the mass number of this element? [tex] { }_{14}^{29} Si [/tex] A. 29 B. 43 C. 14 D. 15

[Answered] Select the best answer for the question. 15. In which of the following cases does an atom have a positive charge? A. There are more electrons than neutrons. B. There are more neutrons than electrons. C. There are more protons than electrons. D. There are more electrons than protons.

[Answered] What mass of NaCl formed when 0.25 g Na react completely with $0.39 g Cl _2$? A. -0.14 g NaCl B. 0.14 g NaCl C. 0.59 g NaCl D. 0.64 g NaCl

[Answered] Your answer is wrong. In addition to checking your math, check that you used the right data and DID NOT round any intermediate calculations. The reduction of iron(III) oxide ( $Fe _2 O _3$ ) to pure iron during the first step of steelmaking, $2 Fe_2 O_3(s) \rightarrow 4 Fe(s)+3 O_2(g)$ is driven by the high-temperature combustion of coke, a purified form of coal: $C(s)+O_2(g) \rightarrow CO_2(g)$ Suppose at the temperature of a blast furnace the Gibbs free energies of formation $\Delta G_f$ of $CO _2$ and $Fe _2 O _3$ are $-415 . kJ / mol$ and $-840 . kJ / mol$, respectively. Calculate the minimum mass of coke needed to produce $440 . t$ of pure iron. (One metric ton, symbol t, equals 1000 kg. ) Round your answer to 2 significant digits.

[Answered] Which is a correct set of values of [tex]$m$[/tex] for one of the subshells of [tex]$n=2$[/tex]? A. [tex]$-1,0,1$[/tex] B. [tex]$-1,-2,0,1,2$[/tex] C. [tex]$-1,-2,-3,0,1,2,3$[/tex] D. [tex]$-1,-2,-3,-4,0,1,2,3,4$[/tex]

[Answered] What mass of [tex]$Cl _2$[/tex] reacted when 0.243 g Mg reacted completely to form [tex]$0.953 g MgCl _2$[/tex]?