CHEMISTRY MIDDLE SCHOOL

Solar energy received by the Earth's surface causes the Earth's surface to heat up during the day. Which of the following heat transfer mechanisms is the main cause of the surface gaining heat? A. radiation B. convection C. conduction D. advection

Answers

Answer 1
Answer:

Answer:

radiation

Explanation:


Related Questions

HIGH SCHOOL

Kp is the equilibrium constant for dissociation of the propionic acid dimer. what is the sign of the slope for a plot of the natural logarithm of kp vs. inverse temperature for this reaction?

Answers

Ans: The sign of the slope is negative

The free energy change (ΔG) is related to the equilibrium constant Kp as:

ΔG = -RTlnKp -------(1)

Also, ΔG = ΔH-TΔS ------(2)

therefore,

-RTlnKp = ΔH-TΔS

ln(Kp) = -ΔH/R(1/T) + ΔS/R

Thus, a plot of lnKp Vs 1/T will give a straight line with a negative slope such that:

Slope = -ΔH/R

Intercept = ΔS/R

HIGH SCHOOL

Calculate ΔHrxn for the following reaction: CH4(g)+2O2(g)→CO2(g)+2H2O(l) Use the following reactions and given ΔH values. CH4(g)+O2(g)→CH2O(g)+H2O(g), ΔH=−284 kJ CH2O(g)+O2(g)→CO2(g)+H2O(g), ΔH=−527 kJ H2O(l)→H2O(g), ΔH= 44.0 kJ

Answers

Answer :

-899Kj

Explanation

ΔHrxn = ΔHproduct - ΔHreactant

ΔHrxn= {ΔHH2O(l) + ΔHCO2} - ΔHCH4

We do not put that of Molecular oxygen in the equation as it is zero

ΔHH2O(g) - ΔHH2O(l) = 44

-527 = {ΔHH2O(g) + ΔHCO2} - ΔH{CH2O}

-284 = {ΔHCH2O + ΔHH2O(g) } -ΔH{CH4}

Adding the last 2 equations together will yield the following:

-527-284 = 2ΔH{H2O}(g) + ΔHCO2 - ΔHCH4

From the second equation,

ΔHH2O(g) = 44 + ΔHH2O(l)

Substitute this in the added equation

-811 = 2(44 + ΔHH2O(l)) + ΔHCO2 - ΔHCH4

-811 = 88 + 2ΔHH2O(l) + ΔHCO2 - ΔHCH4

-899 = 2ΔHH2O(l) + ΔHCO2 - ΔHCH4

The heat of reaction is thus -899kJ

HIGH SCHOOL

Why aren't noble gases included in the trend for electronegativity?

Answers

Noble gases are almost completely unreactive because they have a complete number of electrons on their valence electron level. So noble gases HAVE NO charge, thus they are not included on the electronegativity trend.
They are unreactive becuase noble gases have 8 valence electrons..therefore they are stable. An atom can only contain 8 valence electrons
MIDDLE SCHOOL

10. How were scientists able to discover the Buckyballs in space?

Answers

Answer:

by exploring space then they saw them

MIDDLE SCHOOL

What is the chemical formula for iron(II) hydroxide?
Fe, OH
Fe(OH)
FeOH
0 FeOH

Answers

Answer:  None of the given options .

Explanation:  The chemical formula of Iron (II) hydroxide can be written as

Fe (OH)2

As iron is present in its +2 state and hyrdoxide ion has charge of one negative unit .

Thus iron hydroxide can be written as the above and none of the given options is correct.

None of the above, it is Fe(OH)2
MIDDLE SCHOOL

Which gas is transported by the circulatory system in humans and is used by cells during respiration to release energy stored in food?

Answers

The answer is oxygen
HIGH SCHOOL

A solution is 66.6% phosphoric acid. What is the percent P in the solution? Answer in units of %.

Answers

You are given the percentage of solution of phosphoric acid which is 66.6%. You are required to get the percent P in the solution. The chemical formula of phosphoric acid is H3PO4 and its molar mass is 98 grams per mole. Take a basis of 100 grams of solution so that we will have a 66.6g of H3PO4. To get the P in the solution;  

66.6g H3PO4 (1 mole H3PO4/98g H3PO4)(1mole P/1mole H3PO4)(1mole P/31grams P) = 21.1 grams P  

Percent P = (21.1g P/66.6g H3PO4)*100
Percent P = 31.6%
HIGH SCHOOL

Carbohydrates, more commonly known as sugars, are made up of carbon, oxygen, and hydrogen atoms. The smallest unit of a carbohydrate is a monosaccharide. Two monosaccharides make up a disaccharide, and many monosaccharides make up a polysaccharide. Disaccharides and polysaccharides can be hydrolyzed back into the individual monosaccharide units.Select the statement that is incorrect.a.) Complex sugars are carbohydrates.b.) All carbohydrates have the general formula Cn(H2O)n.c.) Simple sugars are carbohydrates.d.) Carbohydrates contain only carbon, oxygen, and hydrogen atoms.

Answers

Answer:

The incorrect statement is option B and D.

Explanation:

Carbohydrates are more generally is known as the sugars that are composed of the carbon, hydrogen and oxygen atoms. Monosaccharides are the single unit of carbohydrates while disaccharides are the sugars that contain two molecules of the sugar and similarly saccharides with multiple sugars are called polysaccharides. The general chemical formula of the carbohydrates Cn(H2O)n, however the complex sugars does not follow this formula. Amino sugars are contains NH2 in their formula so carbohydrates not necessarily contains only H, O, AND C always.

Thus, the incorrect answer is - option B and D.

MIDDLE SCHOOL

What are the differences between metals, nonmetals, and metal looks in the periodic table?

Answers

Answer:

Metals ionize by electron gain, non-metals ionize by electron loss while metalloids possess properties of both metals and non-metals

Explanation:

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