Answer:
3.65 g / ml correct to 3 sig. fig.
Explanation:
The computation of the concentration required is shown below:
As we know that
[A] = mass of solute ÷ volume of solution
Before that first find the mass of solute
Given that
Initial weight = 5.55g
And,
Final weight = 92.7 g
So,
Mass of KCl is
= 92.7 - 5.55
= 87.15 g ~ 87.2 g
Now the KCi is fully dissolved, so the volume is 23.9 ml
So, concentration is
= 87.2 g ÷ 23.9 ml
= 3.65 g / ml correct to 3 sig. fig.
Answer:
3.84 Ω
Explanation:
From the question given above, the following data were obtained:
Electrical power (P) = 150 W
Voltage (V) = 24 V
Resistance (R) =?
P = IV
Recall:
V = IR
Divide both side by R
I = V/R
P = V/R × V
P = V² / R
Where:
P => Electrical power
V => Voltage
I => Current
R => Resistance
With the above formula (i.e P = V²/R), we can calculate resistance as illustrated below:
Electrical power (P) = 150 W
Voltage (V) = 24 V
Resistance (R) =?
P = V²/R
150 = 24² / R
150 = 576 / R
Cross multiply
150 × R = 576
Divide both side by 150
R = 576 / 150
R = 3.84 Ω
Thus, the resistance is 3.84 Ω
Answer:
3Mg + Fe₂O₃ → 2 Fe + 3MgO
Explanation:
Chemical equation;
Mg + Fe₂O₃ → Fe + MgO
Balanced Chemical equation;
3Mg + Fe₂O₃ → 2Fe + 3MgO
This is the balanced equation. There are three magnesium, two iron and three oxygen atoms are on both side of equation thus it follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
