Answer:
78.14% Pb²⁺ and 21.86% of Cd²⁺
Explanation:
The first titration involves the reaction of both Pb²⁺ and Cd²⁺
In the second titration, as the buffer is HCN/NaCN, the Cd²⁺ precipitates as Cd(CN)₂ and the only ion that reacts is Pb²⁺
In the first titration:
Moles EDTA = Moles Pb²⁺ and Cd²⁺:
28.89mL = 0.02889L * (0.06950moles / L) = 2.008x10⁻³ moles in the aliquot. In the sample:
2.008x10⁻³ moles * (250.0mL / 50.0mL) =
0.01004 moles = Pb²⁺ + Cd²⁺ (1)
In the second titration:
19.07mL = 0.01907L * (0.06950mol / L) = 1.325x10⁻³ moles Pb²⁺ in the aliquot. In the sample:
1.325x10⁻³ moles Pb²⁺ * (250.0mL / 50.0mL) =
6.626x10⁻³ moles Pb²⁺
That means the moles of Cd²⁺ are:
0.01004 moles = Cd²⁺ + 6.626x10⁻³ moles Cd²⁺
3.413x10⁻³ moles Cd²⁺
The mass of each ion is:
Cd²⁺ -Molar mass: 112.411g/mol-:
3.413x10⁻³ moles Cd²⁺ * (112.411g / mol) =
0.384g of Cd²⁺
Pb²⁺ -Molar mass: 207.2g/mol-:
6.626x10⁻³ moles Pb²⁺ * (207.2g / mol) =
1.373g of Pb²⁺
The percent mass of each ion is:
1.373g Pb²⁺ / 1.757g = 78.14% Pb²⁺
And:
0.384g of Cd²⁺ / 1.757g * 100 = 21.86% of Cd²⁺
What is the IUPAC name for the compound shown?
Give the systematic (IUPAC) name for each molecule. This molecule has the condensed formula C H 3 C O C H 3. The oxygen atom has a double bond to the center carbon. systematic (IUPAC) name: This molecule has the condensed formula C H 3 C H 2 C H 2 C O C H 3. The oxygen atom has a double bond to carbon. systematic (IUPAC) name:
Answer: The IUPAC name of [tex]CH_3COCH_3[/tex] propan-2-one and [tex]CH_3CH_2CH_2COCH_3[/tex] is pentan-2-one.
Explanation:
The basic rules for naming of organic compounds are :
1. First select the longest possible carbon chain. The longest possible carbon chain should include the carbons of double or triple bonds or functional group.For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.
2. The naming of alkane is done by adding the suffix -ane, alkene by adding the suffix -ene, alkyne by adding the suffix -yne and ketones by adding the suffix -one.;
3. The numbering is done in such a way that the carbon containing the functional group gets the lowest number. While writing the name, the word root is given first , followed by the position of carbon containing the functional group followed by the suffix.
The IUPAC name of [tex]CH_3COCH_3[/tex] propan-2-one and [tex]CH_3CH_2CH_2COCH_3[/tex] is pentan-2-one.
What is the main difference between rain and hail?
Answer:
Rain is a liquid and hail is a solid.
Identify the reactants and products in the following chemical equation: Zn +2HCl --> ZnCl2 + H2 *
20 points
A: Reactants: Zn & HCl Products: ZnCl2 & H2
B: Reactants: ZnCl2 & H2 Products: Zn & HCl
C: Reactants: Zn & H2 Products: ZnCl2 & HCl
Answer:
A.
Explanation:
zinc and hydrochloric acid reacts to form zinc chloride and hydrogen.
hope it helps. :)
2.56 x 10^13 molecules of HgO equates to how many moles of HgO?
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{2.56 \times {10}^{13} }{6.02 \times {10}^{23} } \\ \\ \\ = 4.25 \times {10}^{ - 11} \: \: \: moles[/tex]
Hope this helps you
An inventor claims to have developed a new perfume that lasts a long time because it doesn't evaporate. Comment on this claim.
a. This would be impossible to make because the perfume would have to be pressurized in order to not evaporate.
b. This product is sure sweep the market making many happy customers.
c. In order to smell something, the molecules must evaporate and reach your nose. If the new perfume doesn't evaporate, it will not have an odor.
d. A perfume that does not evaporate could be toxic since the molecules never leave the skin.
Answer:
C
Explanation:
Perfume needs to evaporate in order to smell. If this perfume didn't evaporate, it would stay as a liquid and never smell.
It wouldn't be D, as no toxic perfumes is sold.
It's not A because perfume doesn't have to be pressurized in order to not evaporate.
It's not B, as it is a hasty conclusion to the claim. Plus, if the perfume did have an odor, even while not evaporating, the sales would be low as the product is that good.
A solution contains some or all of the ions Cu2+, Al3+, K+, Ca2+, Ba2+, Pb2+, and NH4+. The following tests were performed, in order, on the solution.
Addition of 6 M HCl produced no reaction.
Addition of H2S with 0.2 M HCl produced a black solid.
Addition of (NH4)2S produced a white solid.
Addition of (NH4)2HPO4 in NH3 produced no reaction.
The final supernatant when heated produced a purple flame.
Identify which of these ions were present in the solution, which were absent, and for which ones no conclusions can be drawn.
Answer:
See explanation
Explanation:
If we look at the tests to be performed on the compounds carefully, we will notice that;
i) Addition of H2S with 0.2 M HCl produced a black solid. This black solid may result from the reaction;
H2S + Cu2+ ---->CuS(balck solid) + H2
or
H2S + Pb2+ ---->PbS(balck solid) + H2
Hence, Cu2+ or Pb2+ may be present
ii) Addition of (NH4)2S produced a white solid. This means that K^+ may be present because the white precipitate is formed during metathesis.
iii) Potassium ion is known to burn with a purple flame.
Hence the suspected ions are;
Cu2+ , Pb2+ and K^+