Answer:
18 + 81 = 9(x² + 6x + 9) 11 = (x + 3)²
Explanation:
because This is the value that completes the square. However, since the entire square is multiplied by 9, this value must be multiplied by 9 before we can add it across the equals:
18 + 9 (9) = 9 (x² + 6x + 9)
18 + 81 = 9 (x² + 6x + 9)
99 = 9 (x² + 6x + 9)
Dividing both sides by 9, we have:
11 = x² + 6x + 9
11 = (x + 3) ²
It has a positive value.
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Given the reaction equation; ClO3−(aq)+3Cu(s)+6H+(aq)→Cl−(aq)+3Cu2+(aq)+3H2O(l), the cell notation is Cu/Cu2+//ClO3-/Cl/Pt.
<h3>What is an electrochemical cell?</h3>
A electrochemical cell is one in which electrical energy is produced by chemical processess. In this case, the cell reaction equation is; ClO3−(aq)+3Cu(s)+6H+(aq)→Cl−(aq)+3Cu2+(aq)+3H2O(l).The electrode used here is Pt.
Looking at the equation, we can write the notation for the cell reaction as;Cu/Cu2+//ClO3-/Cl/Pt.
Learn more about electrochemical reaction: brainly.com/question/14356798
The mass of the acetic acid is 1.512 g.
<h3 /><h3>What is Molarity?</h3>
molarity is the concentration of a substance in mol per dm³
From the question,
The number of moles contained in the 30 mL vinegar is
- n = (0.84×30)/1000
- n = 0.0252 mol.
the molar mass of vinegar is calculated below.
- m.m of (HC₂H₃O₂) = [1+(12×2)+(1×3)+(16×2)]
- m.m = (1+24+3+32]
- m.m = 60 g/mol.
To calculate the mass of acetic acid, we use the formula below.
- R.m = n×m.m............. Equation 1
Where
- R.m = mass of acetic acid.
Substitute these values into equation 1
- R.m = (0.0252×60)
- R.m = 1.512 g.
Hence, The mass of the acetic acid is 1.512 g.
Learn more about molarity here: brainly.com/question/20383725
Normal distribution curve has the greatest standard deviation.
Standard deviation describes how far from the mean the given data set spread out
