Answer:
about 0.9 mol
Explanation:
there are 22.990 g/mol of Na
20.7/22.99 = 0.900391 mol
about 0.9 mol
50 grams or 50,000 mili grams is the mass of solute in 1000 grams of a solution having a concentration of 5 parts per million.
Explanation:
Total mass of solution = 1000 grams or 1000 ml since 1 gram = 1 ml
concentration is 5 parts per million ( 5 mg in 1000 ml solution or 0.005 gram in 1000 ml)
the formula used for parts per million:
parts per million = 
putting the values in the equation:
parts per million = 
0.005 x 1000 = mass of solute
50 grams= mass of solute
converting this into mg
50,000 mg. is the total mass of solute in 5ppm of 1000 ml solution.
Answer:
Kp = 0.022
Explanation:
<em>Full question: ...With 2.3 atm of ammonia gas at 32. °C. He then raises the temperature, and when the mixture has come to equilibrium measures the partial pressure of hydrogen gas to be 0.69 atm. </em>
<em />
The equilibrium of ammonia occurs as follows:
2NH₃(g) ⇄ N₂(g) + 3H₂(g)
Where Kp is defined as:

<em>Where P represents partial pressure of each gas.</em>
<em />
As initial pressure of ammonia is 2.3atm, its equilibrium concentration will be:
P(NH₃) = 2.3atm - 2X
<em>Where X represents reaction coordinate</em>
<em />
Thus, pressure of hydrogen and nitrogen is:
P(N₂) = X
P(H₂) = 3X.
As partial pressure of hydrogen is 0.69atm:
3X = 0.69
X = 0.23atm:
P(NH₃) = 2.3atm - 2(0.23atm) = 1.84atm
P(N₂) = 0.23atm
P(H₂) = 0.69atm

<h3>Kp = 0.022</h3>
Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.
We have the following equation representing the half-life decay:

A is the resulting amount after t time
Ao is the initial amount = 50 mg
t= Elapsed time
t half is the half-life of the substance = 14.3 days
We replace the know values into the equation to have an exponential decay function for a 50mg sample

That would be the answer for a)
To know the P-32 remaining after 84 days we have to replace this value in the equation:

So, after 84 days the P-32 remaining will be 0.85 mg
Answer:
Be,Mg,Ra etc
Explanation:
It should be palced in group 2A because as it reacts with chlorine in ratio of 1:2 . It's valancy is 2 and is metal as it react with non metal donating two electrons .
one more thing it fits there orderly