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2 years ago

What is the difference between elements, compounds and mixtures in terms of particle theory?

1 answer:

7 0

Element is a single substance, while a compound is the chemical combination of two or more elements, and mixture is the physical combination of two or more elements that can easily be reversed to obtain it's previous state.

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What is potential energy? Give an example please.

FromTheMoon [43]

Answer:

Potential energy can be defined as the energy in a body due to its position

In simple terms potential energy is the energy at rest

Explanation: Examples ;

A spring has more potential energy when it is compressed or stretched.

A steel ball has more potential energy raised above the ground than it has after falling to Earth.

6 0

2 years ago

The vapor pressure of substance X is 100. mm Hg at 1080.°C. The vapor pressure of substance X increases to 600. mm Hg at 1220.°C

artcher [175]

Explanation:

The given data is as follows.

$P_{1}$ = 100 mm Hg or $\frac{100}{760}atm$ = 0.13157 atm

$T_{1}$ = $1080 ^{o}C$ = (1080 + 273) K = 1357 K

$T_{2}$ = $1220 ^{o}C$ = (1220 + 273) K = 1493 K

$P_{2}$ = 600 mm Hg or $\frac{600}{760}atm$ = 0.7895 atm

R = 8.314 J/K mol

According to Clasius-Clapeyron equation,

$log(\frac{P_{2}}{P_{1}}) = \frac{\Delta H_{vap}}{2.303R}[\frac{1}{T_{1}} - \frac{1}{T_{2}}$

$log(\frac{0.7895}{0.13157}) = \frac{\Delta H_{vap}}{2.303 \times 8.314 J/mol K}[\frac{1}{1357 K} - \frac{1}{1493 K}]$

$log (6) = \frac{\Delta H_{vap}}{19.147}[\frac{(1493 - 1357) K}{1493 K \times 1357 K}]$

0.77815 = $\frac{\Delta H_{vap}}{19.147J/K mol} \times 6.713 \times 10^{-5} K$

$\Delta H_{vap}$ = $2.219 \times 10^{5}$ J/mol

= $2.219 \times 10^{5}J/mol \times 10^{-3}\frac{kJ}{1 J}$

= 221.9 kJ/mol

Thus, we can conclude that molar heat of vaporization of substance X is 221.9 kJ/mol.

4 0

2 years ago

How many copper atoms are in 150 g of copper metal

GaryK [48]

1. From grams -> mole:

=grams given x 1 mol/molar mass

So 150 g Cu x 1 mol Cu/63.546 g Cu = 2.4 mol Cu

2. From mole -> atoms

=number of mol x 6.022x10^22 atoms/1 mol

So 2.4 mol Cu x 6.022x10^22 atoms Cu/1 mol Cu = 1.4 x 10^24 atoms Cu

5 0

2 years ago

A scientist adds a liquid to a base. As it is added the substance turns reddish pink the liquid is most likely?

Natalka [10]

Answer:

what we need to answer here?

6 0

3 years ago

Iodine-131 decays with a half-life of 8.02

dlinn [17]

Radioactive material undergoes 1st order decay kinetics.

For 1st order decay, half life = 0.693/k

where k = rate constant

k = 0.693/half life = 0.693/8.02 = 0.0864 day-1

Now, for 1st order reaction,
k = $\frac{2.303}{t} X log \frac{initial.conc}{final.conc}$

Given: t = 6.01d, initial conc. = 5mg

∴0.0864 = $\frac{2.303}{6.01} X log \frac{5}{final.conc}$
∴ final conc. = 2.975 mg

3 0

3 years ago