Answer:
You cannot make observations if you are 57 seconds late into the lab.
Explanation:
The atomic nucleus can split by decay into 2 or more particles as a result of the instability of its atomic nucleus due to the fact that radioactive elements possess an unstable atomic nucleus.
Now, the primary particles which are emitted by radioactive elements in order to make them decay are alpha, beta & gamma particles.
The half life equation is;
N_t = N₀(½)^(t/t_½)
Where:
t = duration of decay
t_½ = half-life
N₀ = number of radioactive atoms initially
N_t = number of radioactive atoms remaining after decay over time t
We are given;
t = 57 secs
N₀ = 100 g
Now, half life of Nitrogen-16 from online sources is 7.2 seconds. t_½ = 7.2
Thus;
N_t = 100(1/2)^(57/7.2)
N_t = 0.4139g
We are told that In order to make observations, you require at least .5g of material.
The value of N_t you got is less than 0.5g, therefore you cannot make observations if you are 57 seconds late.
No
Water’s density is 1 g/cm3 and AL is 2700kg/m3
Answer:
Se
Explanation:
Se is in geoup 6, period 4
N2 + 3 H2 >> 2 NH3
moles NH3 = 11.50 g /17.0307 g/mol=0.6753
the ratio between H2 and NH3 is 3 : 2
moles H2 needed = 0.6753 x 3/2 =1.013
mass H2 = 1.013 mol x 2.106 g/mol=2.042 g
Answer:
hello your question is incomplete attached below is the complete question
a) 0.12 M
b) Ka = 3.0 * 10^-7
c) Alizarin Yellow R
Explanation:
<u>A) Determine the concentration of the unknown acid</u>
The PH of the unknown acid before addition of NaOH is ; 3.72 ( weak acid )
First determine the moles of of NaOH
= molarity * volume
= 0.10 M * 30.0 ML = 0.0030 mol
at equivalence point
moles of NaOH = moles of unknown acid = 0.0030 mol
volume of unknown acid = 25.0 mL
Next calculate the concentration of the Acid ( HA )
= moles / volume
= 0.0030 mol / 25.0 mL
= 0.12 M
<u>b) Determine the Ka of the unknown acid </u>
attached below is the detailed solution
Ka = 3.0 * 10^-7
c) The indicator that would be a good choice to use in the titration of this acid with NaOH is ; Alizarin Yellow R . this is because the titration is between a strong base and a weak acid.
