Question
The system international (SI) unit for energy is:
Answer: joule
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Answer:
32.5g of sodium carbonate
Explanation:
Reaction of sodium carbonate (Na₂CO₃) with Mg²⁺ and Ca²⁺ as follows:
Na₂CO₃(aq) + Ca²⁺(aq) → CaCO₃(s)
Na₂CO₃(aq) + Mg²⁺(aq) → MgCO₃(s)
<em>1 mole of carbonate reacts per mole of the cations.</em>
<em />
To know the mass of sodium carbonate we must know the moles of carbonate we need to add based on the moles of the cations:
<em>Moles Mg²⁺:</em>
2.91L * (0.0661 moles MgCl₂ / 1L) = 0.192 moles MgCl₂ = Moles Mg²⁺
<em>Moles Ca²⁺:</em>
2.91L * (0.0396mol Ca(NO₃)₂ / 1L) = 0.115 moles Ca(NO₃)₂ = Moles Ca²⁺
That means moles of sodium carbonate you must add are:
0.192 moles + 0.115 moles = 0.307 moles sodium carbonate.
In grams (Using molar mass Na₂CO₃ = 105.99g/mol):
0.307 moles Na₂CO₃ * (105.99g / mol) =
<h3>32.5g of sodium carbonate</h3>
Answer:
2.1 M is the molarity of the HCl solution.
Explanation:

Molarity of HCl solution = 
Volume of HCl solution = 
Ionizable hydrogen ions in HCl = 
Molarity of NaOH solution = 
Volume of NaOH solution = 
Ionizable hydroxide ions in NaOH = 
(neutralization )


2.1 M is the molarity of the HCl solution.
Answer: Option (A) is the correct answer.
Explanation:
An element is defined as a substance that contains atoms of same type.
As copper wire is a substance that is made up of only atoms of copper. And, all these atoms of copper will be the same. Hence, it is an element.
This means that all the atoms of copper will have same number of protons, neutrons and electrons.
Thus, we can conclude that the statement they are all exactly the same best describes the copper atoms.
[A]0= Initial concentration
t1/2= half life
[A]= final concentration
k= rate constant