All categories

3 years ago

If the chemical properties of a substance remain unchanged and the appearance or shape of an substance changes it is called a

Chemistry

2 answers:

Akimi4 [234]3 years ago

5 0

Answer:

Explanation:

physical change is the answer I hope

Morgarella [4.7K]3 years ago

3 0

Answer:

Explanation:

it is A because i am really smart

You might be interested in

Consider 2 Al + 6 HCl → 2 AlCl3 + 3 H2 , the reaction of Al with HCl to produce hydrogen gas. What is the pressure of H2 if the

Margaret [11]

Answer : The pressure of hydrogen gas is 8.96 atm.

Explanation :

The given balanced chemical reaction is:

$2Al+6HCl\rightarrow 2AlCl_3+3H_2$

From the balanced chemical reaction we conclude that,

As, 2 moles of Al react to give 3 moles of $H_2$ gas

So, 4.50 moles of Al react to give $\frac{3}{2}\times 4.50=6.75$ moles of $H_2$ gas

Now we have to calculate the moles of $H_2$ gas when percent yield is 75.4.

$\text{The moles of }H_2=75.4\% \times 6.75=\frac{75.4}{100}\times 6.75=5.09moles$

Now we have to calculate the pressure of $H_2$ gas.

Using ideal gas equation :

PV = nRT

where,

P = Pressure of hydrogen gas = ?

V = Volume of the hydrogen gas = 14.0 L

n = number of moles of hydrogen gas = 5.09 moles

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of hydrogen gas = 300 K

Putting values in above equation, we get:

$P\times 14.0L=5.09mol\times 0.0821L.atm/mol.K\times 300K\\\\P=8.96atm$

Therefore, the pressure of hydrogen gas is 8.96 atm.

3 0

2 years ago

Write the chemical symbol for the isotope of cobalt with 37 neutrons

oksano4ka [1.4K]

Answer:

64Co27

Explanation:

4 0

3 years ago

12. A voltaic cell consists of a chromium electrode dipped in a 1.20 M chromium (III) nitrate

Lilit [14]

For a voltaic cell consisting of chromium, an electrode dipped in a 1.20 M chromium (III) nitrate solution and a tin electrode dipped in a 0.400 M tin (II) nitrate solution, the cell potential at 298 K is mathematically given as

Ecell = 0.577 V

<h3 /><h3>What is the cell potential at 298 K?</h3>

Generally, the equation for the Oxidation and Reduction is mathematically given as

Cr(s) ------------------ Cr+3(aq) + 3e- ] x 2 ...O

Sn+2(aq) + 2e- ------------ Sn(s) ] x 3 ...R

Reaction

2 Cr(s) + 3 Sn+2(aq) --------------- 2 Cr+3(aq) + 3 Sn(s)

Therefore

Eicell = - 0.14 - ( - 0.74)

Eicell = 0.60

In conclusion

$Ecell= E0cell - \frac{0.0591}{n} * \frac{log[Cr+3]^2}{ [ Sn+2]^3}$

$Ecell = 0.60 - \frac{0.0591 }{6} \frac{log( 1.20)^2}{ ( 0.200)^3}$

Ecell = 0.577 V

Read more about Temperature

brainly.com/question/13439286

5 0

2 years ago

How many moles of methane (CH4) could be made from 4.6 moles of hydrogen?

DENIUS [597]

Answer:

Number of moles of methane form = 2.3 mol

Explanation:

Given data:

Number of moles of Hydrogen = 4.6 mol

Number of moles of methane form = ?

Solution:

Chemical equation:

C + 2H₂ → CH₄

Now we will compare the moles of methane with hydrogen from balance chemical equation.

H₂ : CH₄

2 : 1

4.6 : 1/2×4.6 = 2.3 mol

Form 3.6 moles of hydrogen 2.3 moles of methane can be formed.

6 0

3 years ago

The reaction of iron with oxygen to form iron oxide is an example of an oxidation–reduction reaction: 4fe + 3o2 → 2fe2o3. in thi

nadya68 [22]

Answer:-

Oxygen gains electrons and is reduced.

Explanation:-

For this reaction the balanced chemical equation is

4Fe + 3O2 --> 2Fe2O3

When Oxygen is present as oxygen gas, the oxidation number of O is Zero since it is the only element present in Oxygen gas.

Similarly Iron is present in Fe with oxidation number Zero.

In the case of Fe2O3, Oxygen has the oxidation number -2 while Iron has +3.

So the oxidation number of Oxygen goes from Zero to -2.

Since the oxidation number decreases Oxygen is reduced.

Since reduction involves gain of electrons, Oxygen gains electrons.

4 0

3 years ago