The answer is true, catalysts increase rates by lowering the activation energy of a reaction. Catalysts lower the reaction energy and so the reaction occurs faster. Enzymes perform the role of biological catalysts. Most metabolic pathways of the body are controlled by enzymes. Enzymes by classification are proteins. <span />
Answer:
1.55×10²² molecules.
Explanation:
We'll begin by calculating the number of mole in 5.32 g of pure lead (Pb). This can be obtained as follow:
Mass of Pb = 5.32 g
Molar mass of Pb = 207 g/mol
Mole of Pb =?
Mole = mass /molar mass
Mole of Pb = 5.32/207
Mole of Pb = 0.0257 mole
Finally, we shall determine the number of molecules in 0.0257 mole of Pb. This can be obtained as follow:
From Avogadro's hypothesis,
I mole of Pb contains 6.02×10²³ molecules.
Therefore, 0.0257 mole will contain = 0.0257 × 6.02×10²³ = 1.55×10²² molecules.
Therefore, 5.32 g of pure lead (Pb) contains 1.55×10²² molecules.
<h3>
Answer:</h3>
1031.4 Calories.
<h3>
Explanation:</h3>
We are given;
Mass of the copper metal = 50.0 g
Initial temperature = 21.0 °C
Final temperature, = 75°C
Change in temperature = 54°C
Specific heat capacity of copper = 0.382 Cal/g°C
We are required to calculate the amount of heat in calories required to raise the temperature of the copper metal;
Quantity of heat is given by the formula,
Q = Mass × specific heat capacity × change in temperature
= 50.0 g × 0.382 Cal/g°C × 54 °C
= 1031.4 Calories
Thus, the amount of heat energy required is 1031.4 Calories.
Answer:
Due to gravitational Force the water exerts more pressure at "ground floor" than at "2nd floor".
Explanation:
Answer:
The volume is increased.
Explanation:
According to <em>Charles' Law</em>, " <em>at constant pressure the volume and temperature of the gas are directly proportional to each other</em>". Mathematically this law is presented as;
V₁ / T₁ = V₂ / T₂ -----(1)
In statement the data given is,
T₁ = 10 °C = 283.15 K ∴ K = 273.15 + °C
T₂ = 20 °C = 293.15 K
So, it is clear that the temperature is being increased hence, we will find an increase in volume. Let us assume that the starting volume is 100 L, so,
V₁ = 100 L
V₂ = Unknown
Now, we will arrange equation 1 for V₂ as,
V₂ = V₁ × T₂ / T₁
Putting values,
V₂ = 100 L × 293.15 K / 283.15 K
V₂ = 103.52 L
Hence, it is proved that by increasing temperature from 10 °C to 20 °C resulted in the increase of Volume from 100 L to 103.52 L.
