Other Chemistry Answers

With regard to the species ¹⁶O^2-, ¹⁹F and ²⁰Ne which statement is true

1. all three species contain 10 electrons
2. The sum of the neutrons in all three species is 27
3. The sum of protons in all three species is 28
4. both fluorine and neon contain 20 neutrons
5. none of the above

What is the importance of standard deviation in chemical analysis?

A sample containing NaBr and KBr only weighs 255 mg.  The sample was dissolved in water and treated with excess AgNO₃.  The precipitate formed was found to weigh 420 mg.  Calculate the % NaBr in the sample. 

The two common chlorides of phosphorus, PCl3 and PCl5, both important in the production of other phosphorus compounds, coexist in equilibrium through the reaction PCl3(g) + Cl2(g) → PCl5(g).

At 250oC, an equilibrium mixture in a 2.50 L flask contains 0.105 g PCl5, 0.220 g PCl3, ande 2.12 g Cl2. What are the values of (a) Kc and (b) Kp for this reaction at 250oC? Write the full computation of your answer.

Chromium (II) sulfate, CrSO4, is a reagent that has been used in certain applications to help reduce carbon-carbon double bonds (C=C) in molecules to single bonds (C-C). The reagent can be prepared via the following reaction.

Zn(s) + K2Cr2O7(aq) + H2SO4(aq) → ZnSO4(aq) + CrSO4(aq) + K2SO4(aq) + H2O

What is the maximum number of grams of CrSO4 that can be made from a reaction mixture containing 3.2 mol Zn, 1.7 mol K2Cr2O7 and 5.0 mol H2SO4? Write the full computation of your answer.

1. A 0.3126 g sample of oxalic acid, H2C2O4, requires 26.21 mL of a particular concentration of NaOH(aq) to complete the following reaction. What is the molarity of the NaOH(aq)? Write the full computation of your answer.

H2C2O4(s) + NaOH(aq) → Na2CsO4(aq) + H2O(l)

Consider a 1.245 g sample of glucose (C₆H₁₂O₆). Calculate the moles of glucose in the sample.

An 11.25 g ethanol is heated from 25 degree C to 52.1 degree C. Calculate the amount of heat absorbed by the ethanol.

a 10.0 liter container holds one of the noble gases, but which one is unknown. The mass of the gas is 25.25 g, while the pressure is 3.05 atm and the temperature is 24 C. Calculate the molar mass and identify the gas

the density of concentrated ammonium hydroxide which contain 28 wt% NH3 is 0.899 g/ml. what volume of this reagent should be dilute to 500ml to make 0.25M NH3?