Chemistry! ! !
1. which of the following solutions would have a ph value greater than 7?
a. [oh-] = 2.4 × 10^-2 m
b. [h3o+] =1.53 × 10^-2 m
c. 0.0001 m hcl
d. [oh^-] = 4.4 × 10^-9 m
2. consider the following equation for an equilibrium system: (attached)
which concentration(s) would be included in the denominator of the equilibrium constant expression?
a. pb(s), co2(g), and so2(g)
b. pbs(s), o2(g), and c(s)
c. o2(g), pb(s), co2(g), and so2(g)
d. o2(g)
3. the oxidation number of the sulfur atom in the so^2- 4 ion is
a. +2.
b. -2.
c. +6.
d. +4.
4. in the following reaction, which is the oxidizing agent? (attached - reaction starts with agno2)
a. agno2
b. cl2
c. koh
d. kcl
5. complete the following nuclear equation (attached w/ choices)
6. which two particles have the same mass but opposite charge?
a. a beta particle and a positron
b. a neutron and a proton
c. a proton and an electron
d. an alpha particle and a proton

Question 1

The correct answer is a.

Explanation

The relationship between and is given by

, We can use and . In a we are given the concentration of [OH] and so we use that to find the pOH, then from pOH we can find the pH.

c. HCl is a strong acid so it dissociates to 0.0001 and 0.0001 , hence

has a pH 12.36 which is greater than 7

Question 2

The correct answer is d .

Explanation

This is because solids and liquids do not appear in the equilibrium constant expression. Since .

For the equation

Question 3

The correct answer is c

In a molecule the oxidation number are assigned to get the sum of a neutral charge or ion. The overall charge of is -2 and in all its compounds oxygen has -2 charge, hence

Question 4

The correct answer is b. An oxidising agent must gain electrons in a reaction, thus it is the one that undergoes reduction.In order find out what is being reduced we write half reactions for molecules that change their state. and are spectactor ions in this reaction.

In the chloride half reaction gains electrons to become ions.

Question 5

The last element D is correct. When a nucleus decays by beta emission it produces a daughter nucleus that has same mass number but different atomic number. Therefore beta-decay will have equation

Question 6

The correct answer is a. A beta particle is an electron because it has a charge of -1 and has same mass as an electron, while a positron is  a particle with the same mass as an electron  but with a positive charge.

2b2t

explanation:

2b2t

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.