Chemistry Answers

Predict the electron configurations of (i) the allyl radical, ⋅CH2CHCH2, (ii) the cyclobutadiene cation C4H4+. Estimate the π-electron binding energy in each case.

In the year 2025, NASA was able to find another planet (XXV) which may be able to sustain

life. In order to determine if the planet’s water can sustain an earth organism’s life, Winkler

method was employed to determine dissolved oxygen content. A water sample from planet

XXV was obtained and then treated with the usual reagents for Winkler titration. A 50.0 mL

aliquot of this sample was titrated with the 0.010196M Na2S2O3 standard solution. It

required 4.16 mL of the titrant to reach the starch endpoint.

A. Calculate the amount of dissolved oxygen in the sample in terms of ppm O2. (FW O2 = 32.00)

How much faster does He atom effuse than N₂ molecule at the same temperature? (MM_He = 2g, MM_N₂ = 28g)

Double Indicator Titration

A groundwater sample was analyzed for its total alkalinity (assume that the alkaline constituents come from Na2CO3, NaHCO3 and NaOH, either alone or a permissible combination). For the analysis, a standardized 0.101M HCl solution was used.

Suppose a 30.0-ml sample required 13.2 ml of the titrant to reach phenolphthalein end point. Another 20.0 ml of the same water sample was titrated using methyl orange indicator and used 24.7 ml of the same titrant.

a. Determine the alkaline components of the sample

b. What are the molar concentrations of each component?

c. If the analyst did not boil the distilled water used to standardize the titrant in the problem, what will be the effect on the percentages of each component? Why?

If the temperature is decreased to 5 °C, what is the volume of the sample if the pressure is increased to 96.0 kPa?

An experiment was carried out to determine the mass of Sodium oxide in a solution sample. The sample was dissolved in water to make 200 cm³ of Sodium hydroxide. This solution required 500 cm³of Sulphuric acid to just neutralize it. The concentration of Sulphuric acid was 0.1mol/dm³ (0.1M)

What is OH- of a solution whose pH is 4.732

What is the OH+ of a solution whose POH =4.70

balloon can have a maximum volume of 3m3 before or bursts.iy is filled with helium at sea level and 30°C to have a volume of 0,5m3.when it finally bursts it reaches a height where the atmospheric pressure is equal to 11 kPa Calculate the temperature in °C when the Balloon bursts

What mass of Thallium has the same number of atoms as 65.2 g of Potassium?