The quantity 0.202 g has ____________________________

Explain why science is a continuous profession of study.

xxMikexx [17]

Science is a continuous profession of study because new ideas are produced based on new evidence. Also, there are different topics of science such as climate change or new cures to different diseases.

3 0

4 years ago

The solubility of lead(ii) chloride is 0.45 g/100 ml of solution. what is the ksp of pbcl2? 4.9 × 10-2 1.7 × 10-5 8.5 × 10-6 4.2

Artyom0805 [142]

Answer:
1.7 * 10^-5

Explanation:
1- get the number of moles of PbCl2:
number of moles = mass / molar mass
number of moles = 0.45 / 278.1 = 1.618 * 10^-3 moles

2- get the concentration of Pb2+:
molarity = number of moles of solute / volume of solution in liters
molarity = (1.618 * 10^-3) / (0.1) = 0.0162 M

3- getting concentration of Cl-:
PbCl2(s) <==> Pb2+(aq) + 2Cl-(aq)
We can note that:
For a certain amount of Pb2+ formed, twice this amount of Cl- is formed.
This means that:
for 0.0162 M of Pb2+, 2*0.0168 = 0.0324 M of Cl- is formed

4- getting Ksp:
Ksp = [Pb2+][Cl-]²
Ksp = (0.0162)*(0.0324)²
Ksp = 1.7 * 10^-5

Hope this helps :)

7 0

4 years ago

What are examples of inferred energy?

Kisachek [45]

Using a stove to heat up water.

6 0

3 years ago

Read 2 more answers

A solution containing aluminium ions forms a white precipitate when a few drops of dilute sodium hydroxide solution are added to

Otrada [13]

Answer:

See explanation

Explanation:

A word equation tries to depict a chemical reaction in words. Letters rather than only chemical formulas are used to show the reaction equation.

Now we want to write a word equation that shows the reaction of sodium hydroxide solution and aluminium sulphate solution:

Alumunium sulphate + sodium hydroxide ------>Aluminium hydroxide + sodium sulphate

7 0

3 years ago

Using the following reaction (depicted using molecular models), large quantities of ammonia are burned in the presence of a plat

Mila [183]

Answer:

17.65 grams of O2 are needed for a complete reaction.

Explanation:

You know the reaction:

4 NH₃ + 5 O₂ --------> 4 NO + 6 H₂O

First you must know the mass that reacts by stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction). For that you must first know the reacting mass of each compound. You know the values of the atomic mass of each element that form the compounds:

N: 14 g/mol
H: 1 g/mol
O: 16 g/mol

So, the molar mass of the compounds in the reaction is:

NH₃: 14 g/mol + 3*1 g/mol= 17 g/mol
O₂: 2*16 g/mol= 32 g/mol
NO: 14 g/mol + 16 g/mol= 30 g/mol
H₂O: 2*1 g/mol + 16 g/mol= 18 g/mol

By stoichiometry, they react and occur in moles:

NH₃: 4 moles
O₂: 5 moles
NO: 4 moles
H₂O: 6 moles

Then in mass, by stoichiomatry they react and occur:

NH₃: 4 moles*17 g/mol= 68 g
O₂: 5 moles*32 g/mol= 160 g
NO: 4 moles*30 g/mol= 120 g
H₂O: 6 moles*18 g/mol= 108 g

Now to calculate the necessary mass of O₂ for a complete reaction, the rule of three is applied as follows: if by stoichiometry 68 g of NH₃ react with 160 g of O₂, 7.5 g of NH₃ with how many grams of O₂ will it react?

$mass of O_{2} =\frac{7.5 g of NH_{3} * 160 g of O_{2} }{68 g of NH_{3} }$

mass of O₂≅17.65 g

17.65 grams of O2 are needed for a complete reaction.

3 0

3 years ago

The quantity 0.202 g has _____________________________ significant figures.