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3 years ago

Pls help due in 5 minutes

2 answers:

7 0

The hemisphere tilted most toward our home star sees its longest day, while the hemisphere tilted away from the sun sees its longest night. During the Northern Hemisphere's summer solstice—which always falls around June 21—the Southern Hemisphere gets its winter solstice.

Sveta_85 [38]3 years ago

4 0

Answer:

Explanation:

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Which statement defines reduction potential when considering a pair of half-cell reactions?

torisob [31]

Reduction is the gain of electrons, then potential of reducción is the tendency of a sustance to gain electrons. In this case the sustance is an electrode.

Then the reduction potential refers to the tendency of one electrode to gain electrons and it is measured against a standard electrode which is the electrode of hydorgen.

When you consider the pair of half-cell reactions, the potential of the cell is the reduction potential - oxidation potential.

3 0

3 years ago

In a test of an automobile engine 1.00 L of octane (702 g) is burned, but only 1.84 kg of carbon dioxide is produced. What is th

Reptile [31]

Answer:

The % yield of CO2 is 85.05 %

Explanation:

Step 1: Data given

Mass of octane = 702 grams

Molar mass octane = 114.23 g/mol

Mass CO2 =1.84 kg = 1840 grams

Molar mass of CO2

Step 2: The balanced equation

2C8H18 + 25O2 → 16CO2 + 18H2O

Step 3: Calculate moles of octane

Moles octane = mass octane / molar mass octane

Moles octane = 702.0 grams / 114.23 g/mol

Moles octane = 6.145 moles

Step 4: Calculate moles of CO2

For 2 moles octane we need 25 moles O2 to produce 16 moles CO2 and 18 moles H2O

For 6.145 moles octane we'll have 8*6.145 moles =49.16 moles

Step 5: Calculate mass of CO2

Mass CO2 = moles CO2 * molar mass CO2

Mass CO2 = 49.16 moles * 44.01 g/mol

Mass CO2 = 2163.5 grams

Step 6: Calculate % yield of carbon dioxide

% yield = (actual yield / theoretical yield)*100%

% yield = (1840/2163.5)*100%

% yield = 85.05 %

The % yield of CO2 is 85.05 %

4 0

3 years ago

Help please it's due in 12 hours<br> (20 points)

Rufina [12.5K]

Answer:

1) K and Rb

2) 20 protons, 20 neutrons, and 20 electrons.

Explanation:

1) If it's in the same column, it has the same # of valence electrons (e- on the outer shell), therefore similar chemical properties.

1) atomic #, 20, is the number of protons

2) subtract the mass number from # of protons, which you get 20 neutrons

3) Number of electrons in a neutral atom = number of electrons, which is 20. You can also check yourself by looking at electron configuration on a full periodic table.

8 0

2 years ago

Which activity is the best demonstration of J. J. Thomson’s use of creativity in his work?

frutty [35]

The plum pudding model of the atom by the scientist Sir Joseph John Thompson or J.J. Thompson. It was theorized after the discovery that electrons are present in the atom. In this model, the atom is composed mainly of electrons. It was describe as plum pudding because the electrons are dispersed within the atom. John Dalton discovered the atom. Ernest Rutherford discovered the half – life of an atom and Neils Bohr explain the quantum mechanics. So the answer is J.J. Thompson.

8 0

3 years ago

Read 2 more answers

How many liters of a 0.225 M solution of KI are needed to contain 0.935 moles of KI?

Katyanochek1 [597]

Answer:

4.16L

Explanation:

From the question given, we obtained the following data:

Molarity = 0.225 M

Number of mole of KI = 0.935mole

Volume =?

Molarity = mole / Volume

Volume = mole /Molarity

Volume = 0.935/0.225

Volume = 4.16L

Therefore, 4.16L of KI is needed.

6 0

4 years ago