Answer:
Whether barium chloride solution was pure
Explanation:
We may answer whether barium chloride was pure. The sequence of this experiment might be depicted by the following balanced chemical equations:
Having a total sample of 10.0 grams, we would firstly find the mass percentage of barium in barium chloride:
This means in 10.0 g, we have a total of:
of barium cations.
The precipitate is then formed and we measure its mass. Having its mass determined, we'll firstly find the percentage of barium in barium sulfate using the same approach:
Multiplying the mass we obtained by the fraction of barium will yield mass of barium in barium sulfate. Then:
- if this number is equal to 6.595 g, we have a pure sample of barium chloride;
- if this number is lower than 6.595 g, this means we have an impure sample of barium chloride, as we were only able to precipitate a fraction of 6.595 g.
Answer:
1.Legs
2.Arms and hands
3.Armor
4.Skeletal
5.Carpenters
6.Brain
7.Skin
8.Blood
Explanation:
You can google dem and it will show you all the answers
<u>Answer:</u> The mass of sample A after given time is 99.05 g.
<u>Explanation:</u>
All the radioactive reactions follows first order kinetics.
The equation used to calculate half life for first order kinetics:
We are given:
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = 84.2 s
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = 250 g
[A] = amount left after decay process = ?
Putting values in above equation, we get:
![0.011s^{-1}=\frac{2.303}{84.2s}\log\frac{250}{[A]}](https://tex.z-dn.net/?f=0.011s%5E%7B-1%7D%3D%5Cfrac%7B2.303%7D%7B84.2s%7D%5Clog%5Cfrac%7B250%7D%7B%5BA%5D%7D)
![[A]=99.05g](https://tex.z-dn.net/?f=%5BA%5D%3D99.05g)
Hence, the mass of sample A after given time is 99.05 g.
Answer: <u>The respiratory system </u>
Explanation: It includes the nose, mouth, throat, voice box, windpipe, and lungs. Air enters the respiratory system through the nose or the mouth.
Answer:
X 154
Check solution in explanation
Explanation:
Average atomic mass = ( mass 1× abudance) + ( mass 2× abudance)+ ( mass 3× abudance) / 100
(149×13.8)+(152×44.9) +(154×41.3)/100
2056.2 + 6824.8 + 6360.2/100
=152.412
