Cs -137 has a half life of about 30 years. If 60 years pass, there is two half lives passed so 1/2 * 1/2= 1/4. Take 1/4 and multiply it with the mass given:
(1/4)*20mg=5mg left
Yes it is chemical because it's acid rain and other stuff that is warring it out
Answer : The volume of sodium benzoate and benzoic acid solution mixed to prepare this buffer should be, 29.0 mL and 71 mL respectively.
Explanation :
Let the volume of sodium benzoate (salt) be, x
So, the volume of benzoic acid (acid) will be, (100 - x)
Using Henderson Hesselbach equation :
Now put all the given values in this expression, we get:
x = 29.0
The volume of sodium benzoate = x = 29.0 mL
The volume of benzoic acid (acid) = (100 - x) = (100 - 29.0) = 71 mL
Thus, the volume of sodium benzoate and benzoic acid solution mixed to prepare this buffer should be, 29.0 mL and 71 mL respectively.
Answer is: mass of silver chloride is 34,82 g.
Chemical
reaction: AgNO₃ +
NaCl → AgCl + NaNO₃.
<span>m(AgNO</span>₃) = 53,42 g..<span>
m(NaCl) = 14,19 g.
n(AgNO</span>₃) = m(AgNO₃) ÷ M(AgNO₃).<span>
n(AgNO</span>₃) = 53,42 g ÷ 169,87 g/mol.
n(AgNO₃) = 0,314 mol.
n(NaCl) = 14,19 g ÷ 58,4 g/mol.
n(NaCl) = 0,242 mol; limiting reactant.
From chemical reaction: n(NaCl) : n(AgCl) = 1 : 1.<span>
n</span>(AgCl)<span> = 0,242 mol.
m</span>(AgCl) = 0,252 mol · 143,32 g/mol.
m(AgCl) = 34,82 g.
False The main purpose of using fertilizers are to increase the yielding of the crops. When fertilizers are used, they enable the plants to grow as a faster rate and enhance the quantity of yields obtained from those plants