Answer:
1.72 M
Explanation:
Molarity is the molar concentration of a solution. It can be calculated using the formula a follows:
Molarity = number of moles (n? ÷ volume (V)
According to the information provided in this question, the solution has 58.7 grams of MgCl2 in 359 ml of solution.
Using mole = mass/molar mass
Molar mass of MgCl2 = 24 + 35.5(2)
= 24 + 71
= 95g/mol
mole = 58.7g ÷ 95g/mol
mole = 0.618mol
Volume of solution = 359ml = 359/1000 = 0.359L
Molarity = 0.618mol ÷ 0.359L
Molarity = 1.72 M
<span>12.4 g
First, calculate the molar masses by looking up the atomic weights of all involved elements.
Atomic weight manganese = 54.938044
Atomic weight oxygen = 15.999
Atomic weight aluminium = 26.981539
Molar mass MnO2 = 54.938044 + 2 * 15.999 = 86.936044 g/mol
Now determine the number of moles of MnO2 we have
30.0 g / 86.936044 g/mol = 0.345081265 mol
Looking at the balanced equation
3MnO2+4Al→3Mn+2Al2O3
it's obvious that for every 3 moles of MnO2, it takes 4 moles of Al. So
0.345081265 mol / 3 * 4 = 0.460108353 mol
So we need 0.460108353 moles of Al to perform the reaction. Now multiply by the atomic weight of aluminum.
0.460108353 mol * 26.981539 g/mol = 12.41443146 g
Finally, round to 3 significant figures, giving 12.4 g</span>
Answer:
The answer is the letter A.
Explanation:
It is letter A because of Chlorine needs an electron to have a full shell. So, it will receive a negative one because it is gaining an electron. Potassium lost an electron because the element has to share the electron with Chlorine to balance its properties.
To interpret a graph or chart, read the title, look at the key, read the labels. Then study the graph to understand what it shows. Read the title of the graph or chart. The title tells what information is being displayed.
Hope this helps
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