True or false guys! Please help!
2 answers:
You might be interested in
The unknown substance : Lead
<h3>Further explanation</h3>Given
Density of element
mass of unknown substance = 40 g
volume = 3.5 cm³
Required
The density of unknown substance
Solution
Density is the ratio of mass per unit volume
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:
Input the value to find the density of an unknown substance :
ρ = 40 g : 3.5 cm³
ρ = 11.43 g/cm³
If we look at the table, the substance which has a density of 11.43 is Lead
Answer: 1. Water freezing : is -ve.
2. Water evaporating : is +ve.
3. Crystalline urea dissolving : is +ve.
4. Assembly of the plasma membrane from individual lipids: is -ve.
5. Assembly of a protein from individual amino acids: is -ve.
Explanation:
Entropy is defined as the measurement of degree of randomness in a system.
It is represented by symbol S and we can only measure a change in entropy which is given by .
If there is decrease in randomness , the sign for is -ve and If there is increase in randomness , the sign for
is +ve.
1. Water freezing: Entropy decreases as we move from liquid state to to solid state and thus is -ve.
2. Water evaporating : Entropy increases as we move from liquid state to gaseous state and thus is +ve.
3. Crystalline urea dissolving : The molecules convert from solid and ordered state to aqueous phase and random state. Thus the entropy increases and thus is +ve.
4. Assembly of the plasma membrane from individual lipids: random lipids are associating to form a single large polymer and thus entropy decreases and thus is -ve.
5. Assembly of a protein from individual amino acids: random amino acids are associating to form a single large polymer and thus entropy decreases and thus is -ve.