Calculate how many moles of element Q are in 23.53 g of element Q.

A solution of rubbing alcohol is 68.6 % (v/v) isopropanol in water. How many milliliters of isopropanol are in a 88.2 mL sample

KonstantinChe [14]

From the information given, the total volume of rubbing alcohol is 88.2 ml

68.6 % of this volume is isopropanol.

We will assume 88.2 ml represents 100% volume, so the volume of water will be 31.4 %

The volume of isopropanol is

68.6/100 x 88.2 → 0.686 × 88.2 = 60.505 ml

The volume of isopropanol is 60.5 ml.

Volume of water will be 88.20 - 60.5 = 27.7 ml

(27.7 / 88.2 × 100 = 31.4% )

Adding 60.5 ml of isopropanol to 27.7 ml of water to make up 88.2 ml will give 68.6 % v/v isopropanol to water solution.

8 0

3 years ago

For the simple decomposition reactionAB(g)→ A(g) + B(g)Rate =k[AB]2 and k=0.2 L/mol*s . How long will it takefor [AB] to reach 1

mixer [17]

Answer:

6.66 s will it take for [AB] to reach 1/3 of its initial concentration 1.50 mol/L.

Explanation:

$Rate = k[AB]^2$

The order of the reaction is 2.

Integrated rate law for second order kinetic is:

$\frac{1}{[A_t]} = \frac{1}{[A]_0}+kt$

Where, $[A_0]$ is the initial concentration = 1.50 mol/L

$[A_t]$ is the final concentration = 1/3 of initial concentration = $\frac{1}{3}\times 1.50\ mol/L$ = 0.5 mol/L

Rate constant, k = 0.2 L/mol*s

Applying in the above equation as:-

$\frac{1}{0.5} = \frac{1}{1.50}+0.2t$

$\frac{1}{1.5}+0.2x=\frac{1}{0.5}$

$t = 6.66\ s$

6.66 s will it take for [AB] to reach 1/3 of its initial concentration 1.50 mol/L.

5 0

3 years ago

Which of the following pairs of elements could possibly be in the same group? X has a 1+ ion; Y has a 1- ion. X tends to form a

exis [7]

Let's eliminate these one by one.
The first pair would not be the same, as X would most likely be in group IA, and Y would be in group VIIA, because of their tendency to gain and lose electrons.
The second pair would also violate the same rule, but X would most likely be in group IIA, and Y would most likely be in group VIA.
The third pair would not be the same, as X is most likely in group VIIA, and since Y has eight valence electrons, it is most likely a noble gas.
The final pair has X with atomic number 15, making it phosphorous. Phosphorous wants to gain 3 electrons to have a full octet of 8 outer "valence" electrons, and Y would also like to gain 3 electrons. This means it is possible that the final pair would be in the same group.

5 0

3 years ago

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The reaction between zinc (Zn) and hydrogen chloride (HCl) produces zinc chloride (ZnCl), hydrogen (H2) gas, and heat. If more h

andrew-mc [135]

If more heat is removed from the reaction the rate of reaction change as below to counter the action

The rate of the forward reaction increase and produces more zinc chloride

explanation

The reaction of zinc and HCl to produce ZnCl and H2 is exothermic reaction, heat is produced as one product and by removing heat it favor forward reaction

The position of equilibrium moves to the right since removing heat led to decrease of temperature and more zinc chloride is produced.

6 0

2 years ago

PLS HELP What is one of the benefits that scientists have discovered from organisms' daily exposure to radioisotopes? 1, being a

True [87]

Being able to carbon date fossils

5 0

2 years ago

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