All categories

3 years ago

Explain how you would separate a mixture of water, sand, salt and iron filings into its four component parts.

1 answer:

7 0

You would use the density difference to separate the sand, evaporate the water out (the water vapor will cool back to water if collected). Then use a magnet to get the iron fillings out of the salt.

You might be interested in

What is the length of the pencil in cm?

Levart [38]

Answer:

16 cm

Explanation:

Because when you look at the ruler, it shows the length as 16 cm

7 0

2 years ago

How is stoichiometry used to calculate the amount of product from amount of reactant?

IceJOKER [234]

<span>Stoichiometry deals with the quantitative measurement of reactants and products in a chemical reaction. Let suppose you are given with following reaction;

A + 2 B </span>→ 3 C

According to this reaction 1 mole of A reacts with 2 moles of B to produce 3 moles of C. Now using the concept of mole one can easily measure the amount of reactants reacted and the amount of product formed, as...

1 Mole Exactly equals 6.022 × 10²³ particles

1 Mole of Gas (at STP) exactly occupies 22.4 L Volume

1 Mole of any compound exactly equals the molar mass in grams

Therefore, <span>Stoichiometry is very helpful in quantitative analysis.</span>

6 0

3 years ago

Read 2 more answers

Question 3) A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in LiF. Calculate the pH of the solution after the addition of

Masja [62]

The pH of the solution after adding 0.150 moles of solid LiF is 3.84

<u>Explanation:</u>

We have the chemical equation,

HF (aq)+NaOH(aq)->NaF(aq)+H2O

To find how many moles have been used in this

c= n/V=> n= c.V

nHF=0.250 M⋅1.5 L=0.375 moles HF

Simillarly

nF=0.250 M⋅1.5 L=0.375 moles F

nHF=0.375 moles - 0.250 moles=0.125 moles

nF=0.375 moles+0.250 moles=0.625 moles

[HF]=0.125 moles/1.5 L=0.0834 M

[F−]=0.625 moles/1.5 L=0.4167 M

To determine the problem using the Henderson - Hasselbalch equation

pH=pKa+log ([conjugate base/[weak acid])

Find the value of Ka

pKa=−log(Ka)

pH=−log(Ka) +log([F−]/[HF]

pH= -log(3.5 x 10 ^4)+log(0.4167 M/0.0834 M)

pH=-log(3.5 x 10 ^4)+log(4.996)

pH= -4.54+0.698

pH=-(-3.84)

pH=3.84

The pH of the solution after adding 0.150 moles of solid LiF is 3.84

5 0

3 years ago

Car manufacturers are developing engines that use H₂ as fuel. In Iceland, Sweden, and other parts of Scandinavia, where hydroele

weeeeeb [17]

If the coulombs are supplied at 1.44 V, then 4.766 × 10¹¹ joules are produced.

(a) The reaction is

2H₂O + 2e⁻ → H₂ + 2OH⁻

According to the reaction, 2 moles of electrons flow per mole of reaction,

(b) Given

T = 25°C

Change Celsius into Kelvin

T = 25°C

= (25 + 273 ) K

= 298 K

<h3>What is Ideal Gas Law ?</h3>

It is expressed as

PV = nRT

Hence ,

n = $\frac{PV}{RT}$

= $\frac{(12)(3.5.10^{6} )}{(0.082057)(298)}$

= 1.7176 ×10⁶ mole

Now, From the given reaction we can say that ,1 mole of H₂ is produced by 2 moles of electron

Hence, 1.7176 × 10⁶ mole of H₂ is produced by

= 2 × 1.7176 × 10⁶ moles of electron

= 3.435 ×10⁶ moles of electron

We know that

charge = moles of electron × F

= (3.435 ×10⁶ × 96500) C

= 3.31 × 10¹¹ C

Voltage = $\frac{energy}{charge}$ = $\frac{J}{C}$

1.44 V = $\frac{energy}{3.31 . 10^{11} }$

Energy = 1.44 V × 3.31 × 10¹¹ C

= 4.766 × 10¹¹ Joules

Thus from the above conclusion we can say that, coulombs are supplied at 1.44 V, then 4.766 × 10¹¹ joules are produced.

Learn more about Fuel Cell here : brainly.com/question/16612142

#SPJ4

Disclaimer : The question given was incomplete on portal, Here is the complete question.

Question : Car manufacturers are developing engines that use H₂ as fuel. In Iceland, Sweden, and other parts of Scandinavia countries, where hydroelectric plants produce inexpensive electric power, the H₂ can be made industrially by the electrolysis of water.

a) How many moles of electrons flow per mole of reaction ?

b) How many coulombs are needed to produce 3.53X10⁶ L of H₂ gas at 12.0 atm and 25°C.

c) If the coulombs are supplied at 1.44 V, how many joules are produced?

8 0

1 year ago

Describe the reaction below by listing the

rjkz [21]

Answer:

The covalent bond in Cl₂ is break and combine with sodium to form NaCl through ionic bond.

Explanation:

Chemical equation:

Na + Cl₂ → NaCl

Balanced chemical equation:

2Na + Cl₂ → 2NaCl

The given reaction indicate the formation of sodium chloride.

Sodium chloride is an ionic compound. It is formed by the reaction of chlorine and sodium. The type of bond in Cl₂ is covalent. Both chlorine atoms are tightly held together through sharing of electrons. When sodium chloride is formed the covalent between the chlorine atoms are break and it react with sodium . The chlorine toms thus gain the one electron from the sodium atom and became negative ion while sodium by losing its one valance electrons became positive ions. The strong electrostatic forces are develop between them and ionic bond is formed.

6 0

3 years ago