Chemistry Answers

A lab analysis of 0.502 g of Scandium (Sc) reaction with Oxygen (O2) from Air resulted

in the formation of a metal oxide (MO) which had a mass of 0.768 g.

Find the empirical formula of this metal oxide → Sc?O?

calculate the heat required to boil 325 g of water

if I contain 3 moles of gas in a container with a volume of 60 liters and at a temperature of 400K, what is the pressure inside the container?

Consider a sample of calcium carbonate in the form of a cube measuring 5.093cm on each edge . If the sample has a density of 2.71g.ml^-1 . Calculate the number of moles of calcium carbonate .

2. Which of the following phenomena best illustrates Charles' Law?Explain your answer.

A. Carbon dioxide being dissolved in water B. Expansion of the balloon as it is being submerged in hot water

C. Breathing apparatus being used by a patient

D. Leavening agent causing the fluffiness of cake products

What is the specific heat of a substance if 2440 Joules are required to raise the 

  temperature of a 50g sample?

5g of NaOH and NaCL ( as impurity) were dissolved in 1dm³ of water. If 25cm³ of this solution were neutralized by 21cm³ of 0.1moldm³ HCL. Calculate the mass concentration of NaOH in gdm³.

At 30.0 K, a container has an unknown pressure. What is the new temperature if the pressure is decreased to 33% of the original?

1. Write the hydrolysis reaction for pyridine. identify and define the Bronsted-Lowry acid and base.

2. Why is water considered a Bronsted-Lowry base in the reaction between water and HCI?

3.Define pH and explain how it is related to pOH.

4. The measured pH of the H2SO4 solution in water is 1.8. Calculate the volume of water needed to add to 1.00 L of this solution to increase the pH to 2.55 (The pH scale problem)

5. Determine the concentrations of the hydronium ion in pure water at 50 C if the ion-product of water at 50 C is 3.0x 10^13 ( the acid base properties of water problem )

50 ml of an alkaline water sample requires 3.7 ml of 0.02 N HCL upto phenolphthalein end point and 4.8 ml of complete Neutralization. Find the type and amount of alkalinity in water sample.