Correct Answer: Option g: <span>adding salt to water lowers its freezing point
Reason:
Freezing point is a colligative property. When a non-volatile solution is present in solution, it's freezing point decreases. This is referred as depression in freezing point (</span>ΔTf<span>). Extent of lowering in freezing point is dependent on number of particles present in system. Mathematically it is expressed as:
</span>ΔTf = Kf X m
<span>
where, m = molality of solution
Kf = cryoscopic constant.
Hence, a</span><span>dding salt to water lowers the freezing point of solution.</span>
Ookay
1) T
2) T
3) F
Hope i helped :)
Answer:
15 h
Explanation:
Okay, the first thing that we all have to know before we can answer this question is that this Topic that is, Chemistry of Radioactivity is related to kinetics in a way that Radioactive disintegration follows the first order of Reaction which is under kinetics. So, we will be using the first order kinetics rate law to answer this question. Using the equation (1) below;
k =[ 2.303/ t ]×log ([N°}/ [Nr]) --------(1).
We are given from the question that N° = initial sample = 0.8 mg and Nr= sample remaining = 0.2 and the time taken = t= 30.0 h.
k= (2.303/ 30.0 h ) × log (0.8/0.2).
k=0.076768 h^-1 × log (4).
k= 0.076768 h^-1 × 0.6021.
k= 0.0462 h^-1.
Therefore, using the formula for Calculating half life below for first order kinetics we will be able to find out answer.
k = ln 2/ t(1/2). Where t(1/2) is the half life.
t(1/2) = ln 2/ k.
t(1/2) = ln 2 / 0.0462 h^-1.
t(1/2)= 0.6931/0.0462 h^-1.
t(1/2)=15 h
Answer:
(4) 266 moles
Explanation:
We have Dinitrogen Pentoxide N2O5
6.41*10^25 molecules are given
No of Moles of N2O5 = 
= 
= 106.5 mol
Now using Unitary Method
2 Mole of Nitrogen pentoxide require 5 mole of Oxygen to form N2O5
1 mole of N = 
In 106.5 mole of N = 
= 266.25 mole
So, 6.41*10^25 molecules of N2O5 will require 266.25 mole of Oxygen atoms.
<span>Density = mass / volume
3.32 kg = 3320 g
volume mass / density
3320 / 1.11 = 2990.99</span>
