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3 years ago

Why do you think experimenters work in labs instead of the natural world?

Chemistry

1 answer:

kicyunya [14]3 years ago

3 0

Answer:

I think experiments work in a lab better than the natural world because you got all the equipment that you need in the lab

You might be interested in

The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol. How much energy is produced by burning 0.8210 g

bazaltina [42]

The energy produced by burning : -32.92 kJ

<h3>Further explanation</h3>

Delta H reaction (ΔH) is the amount of heat change between the system and its environment

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)

The enthalpy and heat(energy) can be formulated :

$\tt \Delta H=\dfrac{Q}{n}\rightarrow n=mol$

The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol.

The energy released for 0.8210 g of naphthalene :

$\tt Q=\Delta H\times n\\\\Q=-5139.6~kJ/mol\times \dfrac{0.8210~g}{128.17~g/mol}~\\\\Q=-32.92~kJ$

3 0

3 years ago

Two solutions, initially at 24.60 °C, are mixed in a coffee cup calorimeter (Ccal = 15.5 J/°C). When a 100.0 mL volume of 0.100

yulyashka [42]

Answer:

ΔH = -59.6kJ/mol

Explanation:

The reaction that occurs between Ag⁺ and Cl⁻ ions is:

Ag⁺ + Cl⁻ → AgCl(s) + ΔH

To find ΔH we need to obtain moles of reaction and heat released in the reaction because ΔH is defined as heat released per mole of reaction.

<em>Moles of reaction:</em>

Moles of Ag⁺ and Cl⁻ added are:

Ag⁺: 0.100L * (0.100mol / L) = 0.01moles

Cl⁻: 0.100L * (0.200mol / L) 0 0.02 moles

That means limiting reactant is Ag⁺ and moles of reaction are 0.01 moles

<em>Heat released:</em>

To find heat released we must use coffe cup calorimeter equation:

Q = C*m*ΔT

<em>Where C is specific heat of solution (4.18J/g°C), m is the mass of solution (200g because there are 100 + 100mL = 200mL and density of solution is 1g/mL) and ΔT is change in temperature (25.30°C - 24.60°C = 0.70°C).</em>

Replacing:

Q = C*m*ΔT

Q = 4.18J/g°C * 200g * 0.70°C

Q = 585,2J

Is total heat released.

The calorimeter absorbs:

15.5J / °C * 0.7°C = 10.85

Thus, when 0.01 moles reacts, 585.2J + 10.85 = 596.05J are released (Heat released is heat abosrbed by calorimeter + Heat absorbed by water) and ΔH is:

ΔH = 596.05J / 0.01 moles =

ΔH = 59605J / mol =

<em>As heat is released, ΔH < 0.</em>

6 0

4 years ago

Cell membranes are selectively permeable. This means that A. only water can move freely across the cell membrane. B. any substan

MaRussiya [10]

Answer:

C. some substances can move freely across the cell membrane, while others must be transported.

Explanation:

6 0

3 years ago

The temperature of evaporation is much higher for water than for alcohol. Without knowing more about the chemistry of alcohol, w

Valentin [98]

Answer:

Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.

Explanation:

Hydrogen bonding is a kind of intermolecular interaction that occurs when hydrogen is bonded to a highly electronegative atom.

Both water and alcohols exhibit hydrogen bonding. However, alcohols exhibit fewer hydrogen bonds than water.

As a result of this, the temperature of evaporation is much higher for water than for alcohol because hydrogen bonds hold water molecules more closely than alcohol molecules are held.

8 0

3 years ago

PLEASE HELP ME!!! WORTH 20 POINTS!!!

svlad2 [7]

Answer:

You need to heat the mixture to 78.37°C

Explanation:

In distillation, you can separate 2 or more compounds based on their difference in boiling points.

In a mixture of ethanol and water, in theory, you need to heat the mixture to 78.37°C. In this temperature, the ethanol must be evaporated and then condensed in the receiving flask.

5 0

4 years ago