Answer:
C
Explanation:
will silver wires conduct electricity better than copper wires ?
Answer:
It will take 188.06 hours for the concentration of A to decrease 10.0% of its original concentration.
Explanation:
A → B
Initial concentration of the reactant = x
Final concentration of reactant = 10% of x = 0.1 x
Time taken by the sample, t = ?
Formula used :
where,
= initial concentration of reactant
A = concentration of reactant left after the time, (t)
= half life of the first order conversion = 56.6 hour
= rate constant
Now put all the given values in this formula, we get
t = 188.06 hour
It will take 188.06 hours for the concentration of A to decrease 10.0% of its original concentration.
Answer:
approximately 15.1 grams.
Explanation:
The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want.
change 25 grams of potassium chlorate to moles.
calculate the gram molecular mass of potassium chlorate.
Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron.
1 K x 39 grams/mole
+1 Cl x 35.4 grams/ mole
+3 O x 16 grams/ mole
= 122.4 grams / mole Potassium Chlorate
25
122.4
= moles.
2.05 moles of Potassium Chlorate.
There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride.
2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride.
Find the gram molecular mass of Potassium Chloride.
1 K x 39 = 39
+1 Cl x 35.4 = 35.4
= 74.4 grams / mole.
2.05 moles x 74.4 grams/ mole = 15.2 grams
Hope it helps :)
U-238
The number besides the U means its total molar mass. The molar mass of this element is 238
Molar mass= protons + neutrons
This means that 238= 146 + protons
Do 238 - 146
Answer is 92
Answer:
5
Explanation:
Given parameters:
Hydrogen ion concentration = 0.00001M
Unknown:
pH of the solution =?
Solution:
The pH is used to estimate the degree of acidity or alkalinity of a solution. To solve for pH of any solution, we use the expression below;
pH = -log [H⁺]
[H⁺] is the hydrogen ion concentration
pH = -log (1 x 10⁻⁵)
pH = -(-5) = 5
