pH = 6.0
0.000675 M
0.000675 M calcium hydroxide
Create a Java program that asks the user to input a student number. The format of the student number is a sequence of the following:
Four (4) digits
A dash
Two (2) digits
A dash
Three (3) digits
Display a welcome message if the student number is valid; otherwise, show an appropriate error message. Do not copy the welcome message in the sample output.
a random sample of 81 items is taken, producing a sample mean of 47. The population standard deviation is 5.89. construct a 90 confidence interval to estimate the population mean.
Identify the appropriate distribution function if we want to select 20 random numbers between 0 and 9.
An organic compound X contains 40% carbon, 6.7% hydrogen and the rest oxygen. The vapour density of X is 30. The compound reacted with a compound Y and a colourless gas Z which turn limewater milky. On boiling under reflux, the mixture of X and W, gives a sweet smelling liquid G was formed.i. determine the empirical and molecular formula of X.ii. identify Y, Z, W and G.iii. Give the formula of the functional group present in Xiv. Deduce the structure of the compound Xv. Name the reaction which take place between X and W, and write the equation for the reaction of X and W.
An organic compound X contains 40% carbon, 6.7% hydrogen and the rest oxygen. The vapour density of X is 30. The compound reacted with a compound Y and a colourless gas Z which turn limewater milky. On boiling under reflux, the mixture of X and W, gives a sweet smelling liquid G was formed.i. determine the empirical and molecular formula of X.
A 400 mL buffer solution was prepared by reacting sodium acetate, CH3COONa,
with 1.00 M acetic acid, CH3COOH, with a pH of 4.56 Calculate the mass of
CH3COONa required to prepare the solution. Ka CH3COOH= 1.75 x 10-5
Give an example of
a) an endothermic process that is spontaneous
b) an exothermic process that is spontaneous
c) a reversible process
d) an irreversible process