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Questions in chemistry

[Done] How many protons are in oxygen-18? ${ }_8^{18} O A. 8 B. 10 C. 18

[Done] What is the formula for phosphoric acid? A. [tex]$H _3 P$[/tex] B. [tex]$HPO _3$[/tex] C. [tex]$H _3 PO _4$[/tex] D. [tex]$H _3 PO _3$[/tex]

[Done] A student conducted an experiment where she added HCl (a very strong acid) to 4 test tubes containing unknown solutions. She tested the pH of each of the solutions before and after the addition of the acid using pH paper. The color of the pH paper before and after adding acid to the unknown solutions can be seen in the table below. For reference: [tex]$pH 2=$[/tex] red; [tex]$pH 4=$[/tex] orange; [tex]$pH 7=$[/tex] yellow; [tex]$pH 9=$[/tex] green; [tex]$pH 14=$[/tex] purple. | Test Tube | Before adding acid | After adding acid | | --------- | ------------------ | ----------------- | | A | Yellow | Red | | B | Purple | Yellow | | C | Yellow | Yellow | | D | Green | Red | Which of the tubes is the most likely to contain artificial cytoplasm? Multiple Choice Tube D Tube A Tube C Tube B

[Done] The temperature of a 350.0 mL sample of gas increases from 27°C to 277 °C. What is the final volume of the sample of gas if the pressure and amount of gas in the container is kept constant?

[Done] Which is the electronic configuration for oxygen? A. 1s2 2s2 2p1 B. 1s² 2s² 2p3 C. 1s2 2s2 2p4 D. 1s2 2s2 2p6

[Done] What does the 195 represent in the isotope notation? ${ }_{78}^{195} Pt$ A. atomic number B. neutron number C. atomic mass

[Done] How to prepare a 1M ferric chloride solution

[Done] 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. 30. $\times 10^5 Ikg$

[Done] In what form is carbon found in the atmosphere? [tex]$CO _2$[/tex] [tex]$C _6 H _{12} O _6$[/tex] [tex]$H _2 O$[/tex] ATP

[Done] Classify these salts as either soluble or insoluble: $NH_4CI, PbCl_2, BaSO_4, K_2SO_4, Na_2CO_3, NaNO_3, (NH_4)_2CO_3, MgCO_3, AgNO_3, AgCl$.