Answer:
It will take 6.6 hours for 75% of the lead to decay.
Explanation:
The radioactive decay follows first order rate law
The half life and rate constant are related as

The rate law for first order reaction is
![time=\frac{1}{k}(ln[\frac{A_{0}}{A_{t}}]](https://tex.z-dn.net/?f=time%3D%5Cfrac%7B1%7D%7Bk%7D%28ln%5B%5Cfrac%7BA_%7B0%7D%7D%7BA_%7Bt%7D%7D%5D)
Where
A0 = initial concentration = 1 g
At= final concentration = 0.25 g (as 75% undergoes decay so 25% left]

Answer:
24.525 g of sulfuric acid.
Explanation:
Hello,
Normality (units of eq/L) is defined as:

Since the sulfuric acid is the solute, and we already have the volume of the solution (500 mL) but we need it in liters (0.5 L, just divide into 1000), the equivalent grams of solute are given by:

Now, since the sulfuric acid is diprotic (2 hydrogen atoms in its formula) 1 mole of sulfuric acid has 2 equivalent grams of sulfuric acid, so the mole-mass relationship is developed to find its required mass as follows:

Best regards.
Answer:
A.It lowers the melting point of alumina. B.It increases the electrical conductivity. ... Hint: The solution of alumina and cryolite during the electrolysis gives the aluminium at cathode and oxygen at anode. The alumina is a poor conductor of electricity and the fusion temperature of alumina is about 2000∘C.
Answer:
D. Oxidation
Explanation:
In an <em>electrolytic cell</em>, oxidation (the loss of electrons) takes place at the anode. At the cathode reduction takes place.
A mnemonic technique that could be used is that the process that starts with a vowel (Oxidation) takes place at the place that also starts with a vowel (Anode).
Answer:
if its multiple, C and D, if not, C
Explanation:
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