1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nadezda [96]
3 years ago
15

BRAINLIEST IF ANSWERED CORRECTLY WITH EXPLANATION! HELP PLEASE:)

Chemistry
1 answer:
elena-14-01-66 [18.8K]3 years ago
4 0

First question

Pb(NO_3)_2 + KI \rightarrow PbI_2 + KNO_3

Balaneced:

Pb(NO_3)_2 + 2KI \rightarrow PbI_2 + 2KNO_3

Find how many moles potassium iodide it is in 345.0 grams

n_{KI} = \frac{345.0 \ g}{166.0 \ g/mol} = 2.078 \ mole

Find how many moles potassium nitrate there is for 2.078 moles KI

n_{KNO_3} = \frac{2}{2} \cdot n_{KI} = 2.078 \ mole

Find how many grams potassium nitrate there is in 2.078 moles KNO_3

m_{KNO_3} = 2.078 \ mol \cdot 101.1 \ g/mol = 210.1 \ g

Second question

yield \ \% = \frac{experimental}{theoretical} \cdot 100 = \frac{195.3 \ grams}{210.1 \ grams} \cdot 100 = 93.0 \ \%

You might be interested in
What is the mass number of beryllium with 5 neutrons
lesya692 [45]
5+4=9 Your final answer is 9g
4 0
3 years ago
Industrial ethanol (CH3CH2OH) is produced by a catalytic reaction of ethylene (CH2═CH2) with water at high pressures and tempera
Natasha2012 [34]

Answer:

using bond energies = - 37 kJ

using enthalpies of formation = - 45.7 kJ

Explanation:

From the reaction;

CH2═CH2(g) + H2O(g) -------> CH3CH2OH(g)

From the above reaction; there are 4 (C-H) bonds , 1 ( C=C) and 2 (H-O) of ethene which forms 5(C-H) bonds, 1 (C-C) and 1 (C-O) and 1(H-O) bonds.

Using Bond Energies; the heat of the reaction can be written as:

\delta H^0_ {rxn}= ∑ energy of old bond breaking + ∑ energies of the new bond formation.

\delta H^0_ {rxn}= ∑ [(4 * BE_{C-H})  + BE_{C-C}) +  + BE_{O-H})]+ ∑ [(5 * BE_{C-H}) + BE_{C-C}) + BE_{O-H}+ BE_{C-O})]

\delta H^0_ {rxn}= ∑[4*413 kJ)+(614kJ)+(2*647kJ]+ ∑ (5*-413kJ)+(-347kJ)+(-467kJ)+(-358kJ)]

\delta H^0_ {rxn}=  -37 kJ

To calculate the heats of reaction by using enthalpies of formation; we have:

\delta H^0_ {rxn}= ∑ \delta H^0_ {products} -  ∑ \delta H^0_ {reactants}

\delta H^0_ {rxn}= ∑ \delta H^0_ {CH_3CH_2OH} - ∑ \delta H^0_ {CH_2=CH_2+H_2O}

\delta H^0_ {rxn}=  (-235.1 kJ) - [(+52.47 kJ) + (-241.826 kJ)]

\delta H^0_ {rxn}=  -45.7 kJ

6 0
3 years ago
Which of these actions is the BEST evidence that waves can cause objects to move?
Thepotemich [5.8K]
The answer is C: A surfer rides back to the beach on his surf board.

All the others are examples of people doing stuff to the water, C is an example of the water moving something, in this case the water is moving a surfer and his surf board.
8 0
3 years ago
Read 2 more answers
What are the smallest organelles in cell that are not enclosed in a membrance and they make protien
levacccp [35]
Ribosomes.ribosomes are small structures where proteins are made.Although they are not enclosed within a membrane,they are frequently considered organelles. Hope it helps :)
4 0
3 years ago
Question 10 How many oxygen atoms are in the chemical formula Al(PO4)3? O 1 O 12 O 3​
Basile [38]
13 atoms are in the chemical formula AI(PO4)3
hope that helps :-)
5 0
3 years ago
Read 2 more answers
Other questions:
  • When a substance undergoes a chemical change its identity does not change true or false
    5·1 answer
  • Eating of candy is a chemical change? How
    8·1 answer
  • Calculate the entropy change when 4.31 g of H2 reacts with O2 according to the reaction
    12·1 answer
  • Mike is in a hardware store. He hears a large crash and turns toward the noise. He sees a toddler walking by an overturned cart.
    14·2 answers
  • An italian bicycle has its frame size given as 62 cm. What is the grame size in inches
    7·1 answer
  • Ammonia (NH3) is a weak base that reacts with a strong acid to form the ammonium ion, NH4 . In the titration of 15.00 mL of an a
    13·1 answer
  • How do we separate cork and lead​
    14·1 answer
  • Can someone help with this please? greatly appreciated!
    11·1 answer
  • Which two properties apply to most elements that conducts heat: malleable, brittle, highly combustible, has free electrons
    8·1 answer
  • A man can walk at a speed of 20 mi/day. How far will he walk in 5 days?
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!