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2 years ago

Define Mole Concept give 3 Significance of Mole concept

Chemistry

1 answer:

Alex Ar [27]2 years ago

6 0

Answer:

The mole is important because it allows chemist to work with a subatomic world with macro world units and amount. Atoms molecules and formula units are very small and very difficult to work with usually. However the mole allows a chemist to work with amount large enough to use.

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A 13.5g sample of gold is heated, then placed in a calorimeter containing 60g of water. The temperature of water increases from

sweet-ann [11.9K]

Answer:

$T_i~=163.1$ ºC

Explanation:

We have to start with the variables of the problem:

Mass of water = 60 g

Mass of gold = 13.5 g

Initial temperature of water= 19 ºC

Final temperature of water= 20 ºC

Initial temperature of gold= Unknow

Final temperature of gold= 20 ºC

Specific heat of gold = 0.13J/gºC

Specific heat of water = 4.186 J/g°C

Now if we remember the heat equation:

$Q_H_2_O=m_H_2_O*Cp_H_2_O*deltaT$

$Q_A_u=m_A_u*Cp_A_u*deltaT$

We can relate these equations if we take into account that all heat of gold is transfer to the water, so:

$m_H_2_O*Cp_H_2_O*deltaT=~-~m_A_u*Cp_A_u*deltaT$

Now we can put the values into the equation:

$60~g*4.186~J/g{\circ}C*(20-19)~{\circ}C=-(13.5~g*0.13~J/g{\circ}C*(20-T_i)~{\circ}C)$

Now we can solve for the initial temperature of gold, so:

$T_i~=(\frac{60~g*4.186~J/g{\circ}C*(20-19)~{\circ}C}{13.5~g*0.13~J/g{\circ}C})+20$

$T_i~=163.1$ ºC

I hope it helps!

5 0

2 years ago

2 unicellular no autotrophic It uses a flagellum. A. Kingdom animalia B. kingdom fungi B. kingdom plantae D. kingdom protista

Pachacha [2.7K]

I know the answer to the question

8 0

2 years ago

Fluorite is..

denpristay [2]

Fluorite is harder than gypsum but softer than apatite. Thus, the correct option is B.

<h3>What is the hardness of any element?</h3>

The hardness of any element may be defined as the capability of a material to oppose the process of deformation and remains in actual shape precisely.

According to the table of hardness scales by Mohs, the increasing order of given hardness of given elements is as follows:

Gypsum < Fluorite < Apatite.

Therefore, Fluorite is harder than gypsum but softer than apatite. Thus, the correct option is B.

To learn more about the Hardness of elements, refer to the link:

brainly.com/question/23721736

#SPJ1

5 0

1 year ago

A student is preparing to perform a series of calorimetry experiments. She first wishes to determine the calorimeter constant (C

laila [671]

Answer:

First choice: 99 J/K

Explanation:

1) First law of thermodynamic (energy balance)

Heat released by the the hot water (345K ) = Heat absorbedby the cold water (298 K) + Heat absorbed by the calorimeter

2) Energy change of each substance:

General formula:

Heat released or absorbed = mass × Specific heat × change in temperature

density of water: you may take 0.997 g/ ml as an average density for the water.

mass of water: mass = density × volume = 50.0 ml × 0.997 g/ml = 49.9 g

Specif heat of water: 1 cal / g°C

Heat released by the hot water:

Heat₁ = 49.9 g × 1 cal / g°C × (345 K - 317 K) = 49.9 g × 1 cal / g°C × (28K)

Heat absorbed by the cold water:

Heat₂ = 49.9 g × 1 cal / g°C × (317 K - 298 K) = 49.9 g × 1 cal / g°C × (19K)

Heat absorbed by the calorimeter

Heat₃ = Ccal × (317 K - 298 K) = Ccal × (19K)

4) Balance

Heat₁ = Heat₂ + Heat₃

49.9 g × 1 cal / g°C × (28 K) = 49.9 g × 1 cal / g°C × (19 K) + Ccal × (19 K)

Solve for Ccal

Ccal = [49.9 g × 1 cal / g°C × (28 K) - 49.9 g × 1 cal / g°C × (19 K) ] / 19K

Ccal = 23.6 cal/ K

Convert to cal / K to Joule / K

1 cal = 4.18 Joule

23.6 cal / K × 4.18 J / cal = 98.6 J/K

Which rounded to 2 signficant figures leads to 99 J/k, which is the first choice.

4 0

3 years ago

Which element has the electron configuration [Rn] 7s2 5f14 6d4 ?

nexus9112 [7]

Answer:

Rn] 5f14 6d4 7s2 mp: none d: none. Seaborgium ..... Element. Density. Boiling or Melting Point in °C. Electron Configuration. Symbol.

Explanation:

3 0

3 years ago

Read 2 more answers

Define Mole Concept give 3 Significance of Mole concept​

Define Mole Concept give 3 Significance of Mole concept