Answer:....................................................................
Explanation:.............................................................................
Answer: The mass of Cu produced is 4.88 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} ……(1)
Given mass of aluminum = 2.98 g
Molar mass of aluminum = 27 g/mol
Plugging values in equation 1:
\text{Moles of aluminum}=\frac{2.98g}{27g/mol}=0.1104 mol
The given chemical equation follows:
2Al(s)+3CuSO_4(aq)\rightarrow Al_2(SO_4)_3(aq)+3Cu(s)
By the stoichiometry of the reaction:
If 2 moles of aluminum produces 3 moles of Cu
So, 0.1104 moles aluminium will produce = \frac{3}{2}\times 0.1104=0.1656mol of Cu
Molar mass of Cu = 63.5 g/mol
Plugging values in equation 1:
\text{Mass of Cu}=(0.1656mol\times 63.5g/mol)=10.516g
The percent yield of a reaction is calculated by using an equation:
\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100 ……(2)
Given values:
% yield of product = 46.4 %
Theoretical value of the product = 10.516 g
Plugging values in equation 2, we get:
46.4=\frac{\text{Actual value of Cu}}{10.516g}\times 100\\\\\text{Actual value of Cu}=\frac{46.4\times 10.516}{100}\\\\\text{Actual value of Cu}=4.88g
Hence, the mass of Cu produced is 4.88 g
Answer: 1.25 grams of Potassium-40
Explanation: When the amount of a compound is consumed by half, the time passed is called "the half life". This term is particularly important in nuclear chemistry. Potassium-40 is an isotope of potassium element and it is radioactive. As a result, the consumption time of this radioactive isotope is valuable information since radioactive isotopes are detrimental to health and nature.
For example, in this question, within 1.3 billion years, half amount of the potassium-40 disappears. 2.6 billion years ago, there were 5 grams of potassium-40 and when 1.3 billion years pass, half of the 5 grams of potassium-40 will disappear and there will will be 2.5 grams of potassium-40 left (5 grams of potassium-5 grams of potassium*(1/2)[half amount]=2.5 grams of potassium-40 left). As a result, 2.5 grams of potassium-40 is the amount that is present 1.3 billion years ago (2.6 billion years-1.3 billion years [half-life]=1.3 billion years). There will be 1.3 billion years left until today, so we still have to calculate the amount disappeared in 1.3 billion years. Thus, half of the 2.5 grams must disappear in 1.3 billion years left (2.5 grams - 2.5 grams*(1/2)[half amount]=1.25 grams). Finally, we have 1.25 grams of potassium-40 left since 2.6 billion years ago.
A sodium atom forms NA+1 ion by losing two electrons
I'm going to go with Physical.
