The boys can arrive at the conclusion that as temperature increases, a greater mass of copper sulfate is dissolved in water.
<h3>What is an experiment?</h3>
An experiment is a scientific investigation that seeks to obtain cause and effect relationships. There must be a dependent and an independent variable in every experiment.
The average of the temperature readings is; 20 + 30 + 40 + 50 + 60 + 70 + 80/7 = 50
They used an interval of 10 degrees for the temperature readings. The boys should have kept the heating time the same. The independent variable in this experiment is the temperature. The boys can arrive at the conclusion that as temperature increases, a greater mass of copper sulfate is dissolved in water.
Learn more about dependent and independent variables: brainly.com/question/967776
Answer:
mass of HCl = 243.5426 grams
Explanation:
1- we will get the mass of the reacting gold:
volume of gold = length * width * height
volume of gold = 3.2 * 3.8 * 2.8 = 34.048 cm^3 = 34.048 ml<span>
density = mass / volume
Therefore:
mass = density * volume
mass of gold = </span>19.3 * 34.048 = 657.1264 grams
2- we will get the number of moles of the reacting gold:
number of moles = mass / molar mass
number of moles = 657.1264 / 196.96657
number of moles = 3.3362 moles
3- we will get the number of moles of the HCl:
First, we will balanced the given equation. The balanced equation will be as follows:
Au + 2HCl ......> AuCl2 + H2
This means that one mole of Au reacts with 2 moles of HCl.
Therefore 3.3362 moles will react with 2*3.3362 = 6.6724 moles of HCL
4- we will get the mass of the HCl:
From the periodic table:
molar mass of H = 1 gram
molar mass of Cl = 35.5 grams
Therefore:
molar mass of HCl = 1 + 35.5 = 36.5 grams/mole
number of moles = mass / molar mass
Therefore:
mass = number of moles * molar mass
mass of HCl = 6.6724 * 36.5
mass of HCl = 243.5426 grams
Hope this helps :)
Answer:
This phenomenon occurs because the door, being metal and leading to changes in temperature, undergoes proportional and morphological changes, metals face expansion and expansion in the presence of heat, called thermal expansion.
On the other hand, against the cold, thermal contraction is suffered, that is why its volume decreases, and it contracts.
Explanation:
The expansion phenomenon of the door is not linear, since it increases its volume in width and height, therefore simultaneously on the entire surface.
When an area or surface expands, it does so by increasing its dimensions in the same proportion. For example, a metal sheet increases its length and width, which means an increase in area. Area dilation differs from linear dilation in that it involves an increase in area.
The area expansion coefficient is the increase in area that a body of a certain substance experiences, with an area equal to unity, as its temperature rises one degree centigrade. This coefficient is represented by the Greek letter gamma.
Regarding shrinkage, a clear example of this is when a metal foundry or a weld shrinks, sometimes it is difficult to understand with examples like these (doors) because it is little noticeable by our eyes and the dimensional changes for our perspective. it is infima.
Explanation:
Let us assume that the volume of given aqueous solution is 7.5 L.
Therefore, according to Henry's law, the relation between concentration and pressure is as follows.
C = 
where, pressure (P) = 760 torr = 1 atm
According to Henry's law, constants for gases in water at 
are as follows.
= 0.21 atm = 0.21 bar
= 0.78 atm = 0.78 bar
for 
= 
for 
= 
Since, 21% oxygen is present in air so, its mass will be 0.21 g. Similarly, 78% nitrogen means the mass of nitrogen is 0.78 g.
Therefore, concebtrations will be calculated as follows.
Now, we will calculate the number of moles as follows.
mol
mol
As the molar mass of 
= 32 g/mol
Hence, mass of oxygen will be as follows.
Mass of 
= 63.84 mg
As the molar mass of = 28
Mass of 
= 102.5 mg
Thus, we can conclude that mass of oxygen is 63.84 mg and nitrogen is 102.5 mg.
Answer:
Ionic bond is formed by the opposite ions attraction between the 2 atoms in an ionically bonded compound. The two ions i.e. Cation and Anions are formed by oxidation and reduction reactions respectively. General Ionic formula is as follow,
Mⁿ⁺ + Nⁿ⁻ → MN
where;
Mⁿ⁺ = Cation
Nⁿ⁻ = Anion
MN = Salt
Explanation:
Ionic bond is the electrostatic forces of attraction between positively charged cations and negatively charged Anions. These forces are very stronger resulting in increasing several physical properties of Ionic compounds like melting point and boiling point e.t.c.
Example:
Sodium Chloride:
NaCl is formed by Na⁺ cation and Cl⁻ anion as follow,
Oxidation of Na;
2 Na → 2 Na⁺ + 2 e⁻
Reduction of Cl₂;
Cl₂ + 2 e⁻ → 2 Cl⁻
Crystal Lattice formation is as follow,
Na⁺ + Cl⁻ → NaCl
