There are 4 significant figures
The number of years that must be invested at a rate of 7 % to earn$ 303.52 in interest is
8 years
<em><u>calculation</u></em>
- <em><u> </u></em><em>by use of the formula A = P (1+ rt) </em>
- <em> where : A is the final amount = 542 + 303.52 =$ 845.52</em>
<em> P is the principal money to be invested = $ 542</em>
<em> r= rate= 7/100=0.07</em>
<em> t= time required</em>
<em>=$ 845.52=$ 542( 1+ 0.07 t)</em>
- <em>open the bracket</em>
- <em>= $845.53= $542 + $37.94 t</em>
- <em>like terms together</em>
=$ 845.53 -$542 = $37.94 t
=$303.52 =$37.94 t
- divide both side by $37.94
= $303.52/ $ 37.94 = $37.94t/$37.94
t= 8 years
Answer:
A) homotopic and B) enantiotopic
Explanation:
Protons chemically equivalent are those that have the same chemical shift, also if they are interchangeable by some symmetry operation or by a rapid chemical process.
The existence of symmetry axes, Cn, that relate to the protons results in the protons being homotopic, that is chemically equivalent in both chiral and aquiral environments.
The existence of a plane of symmetry, σ, makes the protons related by it, are enantiotopic and these protons will only be equivalent in an aquiral medium; if the medium is chiral both protons will be chemically NOT equivalent. The existence of a center of symmetry, i, in the molecule makes the related protons through it enantiotopic and therefore chemically only in the aquiral medium.
Diastereotopic protons cannot be interconverted by any symmetry operation and they are different, with different chemical displacement.
<span>The answer is (3) esterification. Note that deposition, distillation and sublimation are not chemical changes, they are physical changes, so you can solve this question by elimination if you know that. Regarding sterification it is a well known chemical reaction that consists on the formation of esters from carboxilic acids.</span>
The balanced chemical reaction is expressed as:
<span>4hcl(g)+o2(g)→2h2o(l)+2cl2(g)
To determine the percent yield of the reaction, we need to calculate for the theoretical yield. This is the maximum amount of the product that can be produced from the reaction given the initial amounts of the reactants. First, we identify the limiting reactant as follows:
</span><span>63.1 g of hcl ( 1 mol / 36.46 g ) ( 1 mol O2 / 4 mol HCl) ( 32 g / mol) = 13.85 g O2
17.2 g of o2 ( 1 mol / 32 g ) ( 4 mol HCl / 1 mol O2) ( 36.46 g / mol) = 78.39 g HCl
Therefore, the limiting reactant would be HCl. We use the value for the HCl to calculate for the theoretical yield.
</span>63.1 g of hcl ( 1 mol / 36.46 g ) ( 2 mol Cl2 / 4 mol HCl) ( 70.9 g / mol ) = 61.35 g Cl2
Percent yield = actual / theoretical x 100
= 59.6 / 61.35 x 100
= 97.1%
