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:
Succinic acid
Explanation:
The most common possibility is succinic acid
As it has decimals after whole no till hundredth it contains OH and C in most of the cases .
Let's check for succinic acid
- C4H_6O_6
- 4(12)+4(16)+6
- 64+48+6
- 118u
Yes approximately equal
Molecular formula is.
(CH_2)_2(CO_2H)_2
Answer:
The mass chloride is 2.903 grams
Explanation:
Step1: calculate the moles of FeCl3
moles = molarity x volume in liters
volume in liters = 100 ml /1000 = 0.1 L
molarity = 0.273 M = 0.273 mol / L
moles = 0.273 mol /L x 0.1 L = 0.0273 moles
step 2: find the moles of Cl
since there is 3 atoms of cl in FeCl3
= 3 x 0.0273 =0.0819 moles
Step 3: calculate mass of cl
mass= moles x molar mass
=0.0819 moles x 35.45 g/mol = 2.903 g
What are the animals to choose from?
30% of 107.75 g is 32.325g so there are about 8.08125 mol of He which is
4.86 x 10^24 particles
70% of 107.75 g is 75.425g so there are about .9 mol of Kr which is
5.42 x 10^23 paticles
In the whole sample, there are about 5.41 x 10^24 particles
