Answer:
58.32
Explanation:
The mass number is one mole and for Mg it is 24.306 for O it is 15.999 and for H it is 1.008. because O and H have 2, you multiply them by 2 and add all the numbers and it equals 58.32
Answer:
55.52°
Explanation:
Concept tested: Sine rule of triangles
We need to know the sine rule
- According to sine rule, if the three sides of a triangle are a, b and c and the corresponding angles, A, B and C
- Then,

In this case;
- If we take, a = 5.7 units and A = 70°, and
b= 5 units, B = x°
- Using the sine rule we can find the value of x
Therefore;

Then;



Therefore, X = 55.52°
Therefore, the value of x in the triangle is 55.52°
Answer: The mass density is 1166.36
.
Explanation:
Given: Weight of sample in air
= 500 N
Weight of sample in alcohol
= 200 N
Specific gravity = 0.7 = 
Formula used to calculate Buoyant force is as follows.

Hence, volume of the material is calculated as follows.

where,
= Buoyant force
= specific gravity
g = acceleration due to gravity = 9.81
Substitute the values into above formula.

Now, mass of the material is calculated as follows.

Therefore, density of the material or mass density is as follows.

Thus, we can conclude that the mass density is 1166.36
.
A reaction in which Oxygen (O₂) is produced from Mercury Oxide (HgO) would be a decomposition reaction.
2HgO → 2Hg + O₂
If 250g of O₂ is needed to be produced,
then the moles of oxygen needed to be produced = 250g ÷ 32 g/mol
= 7.8125 mol
Now, the mole ratio of Oxygen to Mercury Oxide is 1 : 2
∴ if the moles of oxygen = 7.8125 mol
then the moles of mercury oxide = 7.8125 mol × 2
= 15.625 mol
Thus the number moles of HgO needed to produce 250.0 g of O₂ is 15.625 mol