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2 years ago

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Chemistry

1 answer:

wlad13 [49]2 years ago

7 0

Answer:

Earth's atmosphere contains a huge pool of nitrogen gas (N2). But this nitrogen is “unavailable” to plants, because the gaseous form cannot be used directly by plants without undergoing a transformation. To be used by plants, the N2 must be transformed through a process called nitrogen fixation.

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At standard temperature and pressure, 1 mole of gas has what volume? A. 2.4 liters B. 22.4 liters C. 42.4 liters D. 76.6 liters

LekaFEV [45]

Answer: B.22.4 liters

Explanation:

When we attribute to a certain fixed mass of a given gas a fixed number of molecules. Avogadro considered that the mass of 36g of oxygen at any temperature and pressure would have a fixed number of molecules to which he called 1 mol of molecules. So by definition 1 mole of molecules would have a number of molecules equal to that present in 36 g of oxygen. The occupied volume by one mole of molecules at a given temperature and pressure is called molar volume and consists in 22,4 Liters. The molar volume matches the Avogadro Hypothesis (created in 1811 by Amedeo Avogadro), where equal volumes of different gases, at the same temperature and pressure, have even number of moles.

8 0

3 years ago

In sodium chloride the ions are lined up in a __ patterns

adelina 88 [10]

Random or ionic bond pattern

6 0

3 years ago

A 100.00 ml of volume of 0.500 M HCl was mixed with 100.00 ml of 0.500 M KOH in a constant pressure calorimeter. The initial tem

Virty [35]

Answer:

The heat of the reaction = -1985 J = -1.985 kJ

The enthalpy of the reaction is -39.7 kJ/ mol

Explanation:

Step 1: Data given

Volume of HCl = 100 mL the heat of the reaction = 0.1 L

Molarity of HCl solution = 0.500 M

Volume of KOH = 100 mL = 0.1 L

Molarity of KOH solution = 0.500 M

Initial temperature = 23.0 °C

Final temperature = 25.5 °C

Specific heat of the solution = 3.97 J/°C *g

Density of the solution = 1g/ mL

Step 2: Calculate heat

Q = m*c*ΔT

with m = the mass of both solution : 100g + 100 g ( since density = 1g/mL) = 200 g

c = the specific heat = 3.97 J/°C*g

ΔT = T2 -T1 = 25.5 = 23 = 2.5 °C

Q = 200g *3.97 J/°C*g * 2.5°C = 1985 J (= -1985 J because it's exothermic)

Step 3: Calculate the number of moles

Number of moles = Molarity * Volume

Number of moles = 0.5 * 0.1 L = 0.05 moles

(Moles of the acid are equal to the moles of water produced.

Moles of solution = 0.05 moles)

Step 4: Calculate the enthalpy of the reaction

ΔH = heat change /Number of moles

= -1.985 kJ/ 0.05 moles

=- 39700 J/mol = -39.7 kJ/ mol

The enthalpy of the reaction is -39.7 kJ/ mol

The enthalpy of the reaction is negative, this means the reaction is exothermic ( which means the final temperature is higher than the initial temperature.)

7 0

3 years ago

Ca+HCI—>CaCI2+H2, what is the reaction?

arsen [322]

Answer:

single replacement reaction

Explanation:

This is a kind of single replacement reaction where you switch either cations or anions. Here you switched Ca for H and produced Cacl2 and H2 gas by itself.

4 0

3 years ago

Read 2 more answers

Why are chemists interested in studying thermochemistry? a. Heat is often absorbed during reactions.b. Heat is often released du

Wittaler [7]

Answer:

a. Heat is often absorbed during reactions.

c. Heat is often released during chemical reactions.

Explanation:

Thermochemistry -

The study of thermochemistry involve the change in the amount of heat , during any physical or chemical process , is referred to as thermodynamics .

The focus of thermochemistry is on the changing amount of energy in the form of heat , on the system with respect to the surroundings .

The process like boiling , melting , sublimation , may require energy or releases energy , and hence are studied under thermochemistry .

Hence , from the given question ,

The correct options are - a , c.

6 0

3 years ago