B, they then interpret that data to find their answers
Answer:
The identity of an atom is determined my the number of <u>protons</u>. This is the <u>atomic number</u>.
The particle(s) found inside the nucleus are called <u>protons and neutrons</u>. Their combined mass is referred to as <u>the mass number</u>.
Isotopes have the same number of <u>protons</u>, but different number of <u>neutrons</u>.
Answer:
![[H^+]=0.000285](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D0.000285)

Explanation:
In this, we can with the <u>ionization equation</u> for the hydrazoic acid (
). So:

Now, due to the Ka constant value, we have to use the whole equilibrium because this <u>is not a strong acid</u>. So, we have to write the <u>Ka expression</u>:
![Ka=\frac{[H^+][N_3^-]}{[HN_3]}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BH%5E%2B%5D%5BN_3%5E-%5D%7D%7B%5BHN_3%5D%7D)
For each mol of
produced we will have 1 mol of
. So, we can use <u>"X" for the unknown</u> values and replace in the Ka equation:
![Ka=\frac{X*X}{[HN_3]}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7BX%2AX%7D%7B%5BHN_3%5D%7D)
Additionally, we have to keep in mind that
is a reagent, this means that we will be <u>consumed</u>. We dont know how much acid would be consumed but we can express a<u> subtraction from the initial value</u>, so:

Finally, we can put the ka value and <u>solve for "X"</u>:



So, we have a concentration of 0.000285 for
. With this in mind, we can calculate the <u>pH value</u>:
![pH=-Log[H^+]=-Log[0.000285]=3.55](https://tex.z-dn.net/?f=pH%3D-Log%5BH%5E%2B%5D%3D-Log%5B0.000285%5D%3D3.55)
I hope it helps!
no, u will have to soak then in order for them to die
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.
![pOH= -log [2.4 \times 10^-^2] = 1.62\\\\pH = 14 - 1.62= 12.38](https://tex.z-dn.net/?f=pOH%3D%20-log%20%5B2.4%20%5Ctimes%2010%5E-%5E2%5D%20%3D%201.62%5C%5C%5C%5CpH%20%3D%2014%20-%201.62%3D%2012.38)

c. HCl is a strong acid so it dissociates to 0.0001
and 0.0001
, hence
![pH= -log[0.0001] = 4](https://tex.z-dn.net/?f=pH%3D%20-log%5B0.0001%5D%20%3D%204)
![d.pOH= -log [4.4 \times 10^-9] = 8.36\\\\pH= 14- 8.36 = 5.64](https://tex.z-dn.net/?f=%20d.pOH%3D%20-log%20%5B4.4%20%5Ctimes%2010%5E-9%5D%20%3D%208.36%5C%5C%5C%5CpH%3D%2014-%208.36%20%3D%205.64)
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

![K= \frac{[CO_2][SO_2]}{[O_2]}](https://tex.z-dn.net/?f=K%3D%20%5Cfrac%7B%5BCO_2%5D%5BSO_2%5D%7D%7B%5BO_2%5D%7D)
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.