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TEA [102]
2 years ago
13

1a. A researcher accidentally spilled some sand into his beaker containing crystalline compound X. Knowing what he did about mel

ting points, he was not worried about obtaining the melting point of compound X with a few grains of sand present. Why
Chemistry
1 answer:
Sunny_sXe [5.5K]2 years ago
7 0

Answer:

See explanation

Explanation:

Many organic compounds have low melting points. This is due to the fact that many of these compounds are non polar.

However, compound X is slightly polar but still has a melting point which is far less than that of sand composed of a high melting point inorganic material.

Since sand has a much higher melting point compared to compound X, the researcher need not be worried that sand was spilled into his beaker.

You might be interested in
Na2CO3 reacts with dil.HCl to produce NaCl, H2O and CO2. If 21.2 g of pure Na2CO3 are added in a solution containing 21.9g HCl ,
puteri [66]

Answer:

See explanation

Explanation:

Equation of the reaction;

Na2CO3(aq) + 2HCl(aq) -------> 2NaCl(aq) + H2O(l) + CO2(g)

Number of moles of Na2CO3 = 21.2g/106g/mol = 0.2 moles Na2CO3

Number of moles of HCl = 21.9g/36.5g/mol = 0.6 moles of HCl

1 mole of Na2CO3 reacts with 2 moles of HCl

0.2 moles of Na2CO3 reacts with 0.2 × 2/1 = 0.4 moles of HCl

Hence Na2CO3 is the limiting reactant

Since there is 0.6 moles of HCl present, the number of moles of excess reagent=

0.6 moles - 0.4 moles = 0.2 moles of HCl

1 mole of Na2CO3 forms 1 mole of water

0.2 moles of Na2CO3 forms 0.2 moles of water

Number of molecules of water formed = 0.2 moles × 6.02 × 10^23 = 1.2 × 10^23 molecules of water

1 mole of Na2CO3 yields 1 mole of CO2

0.2 moles of Na2CO3 yields 0.2 moles of CO2

1 mole of CO2 occupies 22.4 L

0.2 moles of CO2 occupies 0.2 × 22.4 = 4.48 L at STP

Hence;

V1=4.48 L

T1 = 273 K

P1= 760 mmHg

T2 = 27°C + 273 = 300 K

P2 = 760 mmHg

V2 =

P1V1/T1 = P2V2/T2

P1V1T2 = P2V2T1

V2 = P1V1T2/P2T1

V2 = 760 × 4.48 × 300/760 × 273

V2= 4.9 L

The limiting reactant is the reactant that determines the amount of product formed in a reaction. When the limiting reactant is exhausted, the reaction stops.

8 0
3 years ago
Compare and contrast histosols and aridosols, the soils of bogs and peat marshes versus those of deserts and arid regions respec
Nat2105 [25]

Answer:

The histosols of peat pogs are soils rich in organic material but poor in mineral nutrients, and are not fertile. Conversely, aridosols (desert soils) have an abundance of mineral nutrients but a dearth of organic matter and are also not fertile.

hope i help✨!

7 0
2 years ago
For the decomposition of hydrogen peroxide in dilute sodium hydroxide at 20 °C 2 H2O2(aq)2 H2O(l) + O2(g) the following data hav
saul85 [17]

Answer:

K= 0.06611

Explanation: The rate of reaction is defined as the change in concentration of any of reactant or products per unit time. From the given reaction, the rate of reaction may be equal to the rate of disappearance of reactant which is equal to the rate of appearance of products.

The average rate of disappearance of H2O2 over the time period from t=0 min at 8.92×10^-2 to t=9.63min at 4.72×10^-2 is given as -4.36×10^-3Mmin-1.

We can say:

•The initial concentration [H2O2]o is 8.92×10^-2M

•The concentration at time t. [H2O2]t is 4.72×10^-2

•The time (t) is 9.63 min

The expression of rate constant for a first order reaction is shown as

K=2.303/t log[H2O2]o/ [H2O2]t

Substitute the values of t, [H2O2]o and [H2O2]t in the equation of rate constant.

K=2.303/9.63 log [8.92×10^-2]/ [4.72×10^-2]

K= 0.2391 (log 8.92×10^-2 - log 4.72×10^-2)

K= 0.2391 [-1.0496-(-1.3261)]

K= 0.2391 (-1.0496+1.3261)

K= 0.2391 (0.2765)

K= 0.06611

Since the value of k is almost constant, the decomposition of H2O2 is a first order reaction.

4 0
3 years ago
describe the number of protons, neutrons, and electrons in the atom, where each type of particle is located​
Sever21 [200]

Answer:

Protons - positive charge located in the nucleus

Neutrons - neutral charge located in the nucleus

Electrons - negative charge located outside the nucleus (they orbit)

6 0
3 years ago
How many atoms are in 3.5 moles of He?
Volgvan

Answer:

The answer is 2.107 × 10²⁴ He atoms

Explanation:

To find the number of atoms given the number moles we use the formula

<h3>N = n × L</h3>

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

N = 3.5 × 6.02 × 10²³

We have the final answer as

<h3>2.107 × 10²⁴ He atoms</h3>

Hope this helps you

4 0
3 years ago
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