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3 years ago

Which material has a crystalline structure at room temperature ( 20 degrees Celsius )

Chemistry

2 answers:

Sauron [17]3 years ago

8 0

It's 2, glass. Water, nitrogen, and sucrose don;t have a crystalline structure.

Musya8 [376]3 years ago

8 0

Answer:

Sucrose. Option 4 is correct.

Explanation:

Crystallinity can be defined as the degree of structural order in a solid.

Let us take a look at each of the material mentioned in the question..

The first one is WATER. Water has the molecular formula of H2O, it is bent at an angle approximately 104.5 degrees. Because of its molecular form as liquid, WATER is amorphous and NOT crystalline.

The second material is GLASS: GLASS do not crystallized when they become hardened.

The third material is Nitrogen, NITROGEN is a non metallic element of group 15. Although solid nitrogen have crystalline modifications, they still exist as amorphous.

The fourth material is sucrose. SUCROSE is a disaccharide. It is a crystalline white solid.

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Calculate the relative formula/atomic mass of each of the following compounds:

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2. FeS (Fe:56, S:32) ---> 56+32 = 88
3. Cl2 (Cl:35.5) ---> 35.5 x 2 = 71
4. CaC03 (Ca:40, C: 12, O: 16) ---> 40 + 12 + 3(16) = 100
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3 years ago

Which statement can best be concluded from the ideal gas law?

schepotkina [342]

The temperature, pressure and volume of a gas are all related

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3 years ago

Read 2 more answers

Calculate the standard reaction enthalpy for the reaction NO2(g) → NO(g) + O(g) given +142.7 kJ/mol for the standard enthalpy of

bulgar [2K]

Answer:

The standard reaction enthalpy for the given reaction is 235.15 kJ/mol.

Explanation:

$O_2(g) \rightarrow \frac{2}{3}O_3(g),\Delta H^o_{1}=142.7 kJ/mol$ ..[1]

$O_2(g) \rightarrow 2 O(g),\Delta H^o_{2}=498.4 kJ/mol$ ..[2]

$NO(g) + O_3(g)\rightarrow NO_2(g) + O_2(g) ,\Delta H^o_{3} = -200 kJ/mol$ ..[3]

$NO_2(g)\rightarrow NO(g) + O(g),\Delta H^o_{4}=?$ ..[4]

Using Hess's law:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

2 × [4] = [2]- (3 ) × [1] - (2) × [3]

$2\times \Delta H^o_{4}=\Delta H^o_{2} -3\times \Delta H^o_{1}-2\times \Delta H^o_{3}$

$2\times \Delta H^o_{4}=498.4 kJ/mol-3\times 142.7 kJ/mol-2\times -200 kJ/mol$

$2\times \Delta H^o_{4}=470.3 kJ/mol$

$\Delta H^o_{4}=\frac{470.3 kJ/mol}{2}=235.15 kJ/mol$

The standard reaction enthalpy for the given reaction is 235.15 kJ/mol.

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3 years ago

A student wants to collect data during an experiment about the transfer of kinetic energy in a sample of water and ice. Which to

erastova [34]

Given what we know, the tool in question that will help the student collect data regarding the transfer of kinetic energy between water and ice would be a thermometer.

<h3>How does the thermometer measure kinetic energy?</h3>

It does not do so directly. However, kinetic energy in water molecules is reflected in the temperature of the water. When water molecules increase their kinetic energy and move more, they become hotter. Increased or decreased heat is an indirect way to measure the transfer of kinetic energy in water.

Therefore, given that the temperature of the water is a reflection of the transfer of kinetic energy happening, we can confirm that the tool that will help the student collect the data needed is a thermometer.

To learn more about kinetic energy visit:

brainly.com/question/999862?referrer=searchResults

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3 years ago