They help bring about chemical reactions. This is because enzymes act as catalysts, lowering the activation energy required for a chemical reaction to initiate. It is in this way that they bring about chemical reactions.
Answer:
4.81×10¹⁰ atoms.
Explanation:
We'll begin by converting 3.2 pg to Ca to grams (g). This can be obtained as follow:
1 pg = 1×10¯¹² g
Therefore,
3.2 pg = 3.2 pg × 1×10¯¹² g / 1 pg
3.2 pg = 3.2×10¯¹² g
Therefore, 3.2 pg is equivalent to 3.2×10¯¹² g
Next, we shall determine the number of mole in 3.2×10¯¹² g of Ca. This can be obtained as follow:
Mass of Ca = 3.2×10¯¹² g
Molar mass of Ca = 40.08 g/mol
Mole of ca=.?
Mole = mass /molar mass
Mole of Ca = 3.2×10¯¹² / 40.08
Mole of Ca = 7.98×10¯¹⁴ mole.
Finally, we shall determine the number of atoms present in 7.98×10¯¹⁴ mole of Ca. This can be obtained as illustrated below:
From Avogadro's hypothesis,
1 mole of Ca contains 6.02×10²³ atoms.
Therefore, 7.98×10¯¹⁴ mole of Ca will contain = 7.98×10¯¹⁴ × 6.02×10²³ = 4.81×10¹⁰ atoms.
Therefore, 3.2 pg of Ca contains 4.81×10¹⁰ atoms.
Answer:
32
Explanation:
The vapour density of a gas is the number of times a given volume of gas or vapour is as heavy as the same volume of hydrogen at a particular temperature and pressure.
Vapour density = 2 × relative molecular mass of the gas or vapour
Relative molecular mass of SO2 = 32 + 2(16) = 64
Hence;
Vapour density of SO2 = 64/2
Vapour density of SO2 = 32
The pressure, in mmHg, exerted by only the oxygen gas is 720.8 mmHg
<h3>Pressure of gas collected over water</h3>
The total pressure of a gas collected over water is given by P = P' + p where
- P = pressure of oxygen gas and
- p = vapour pressure of water at 25 °C = 25 mmHg
Making P' subject of the formula, we have
P' = P - p
Since the total pressure of oxygen plus water vapor is P = 745.8 mmHg, substituting the values of the variables into the equation, we have
P' = P - p
P' = 745.8 mmHg - 25 mmHg
P' = 720.8 mmHg
So, the pressure, in mmHg, exerted by only the oxygen gas is 720.8 mmHg
Learn more about pressure of gas collected over water here:
brainly.com/question/25815247
Answer:
Explanation:
The fundamental units of a measurement is known as its base unit. The units of these substances serves as the base through which other quantities depends. Examples of such quantities are mass, length, time, electric current, temperature, amount of substance and luminous intensity.
Derived units are those that results from the combination of the fundamental or basic units. Examples of derived quantities are force, volume, density, pressure e.t.c.
Derived units of Density:
kgm⁻³
gcm⁻³
Derived unit of volume:
m³
cm³
mL
L
dm³
