Answer:
The answer is
<h2>19.31 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass of gold = 475.09g
volume = 24.6 cm³
The density of the gold is

We have the final answer as
<h3>19.31 g/cm³</h3>
Hope this helps you
I’m pretty sure that they mostly design building structures!
Answer:
The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups.
Explanation:
Answer: Temperature final = 103 °C
Explanation: To solve for final temperature we use the equation of heat:
Q= mc∆T
Next derive the equation to find final temperature
Q = mc(T final - T initial)
Q / mc = T final - T initial
Transpose T initial and change the sign so that T final will be left.
T final = Q / mc + T initial
Substitute the values:
T final = 305 J / 28.8 g x 0.128 J/(g°C)
= 305 J / 3.6864 J/°C
= 82.7 + 20.0°C
= 103 °C final temperature.
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.