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3 years ago

What is the main source(s) of energy for all living things?

Chemistry

2 answers:

svlad2 [7]3 years ago

8 0

I would say the sun.

storchak [24]3 years ago

3 0

Answer:

The sun

Explanation:

All living things get energy from different sources (a cow gets it from grass, dog gets it from meat), but eventually, most energy on Earth comes from the Sun. Plants use it to perform photosynthesis, other organisms eat plants, and so on!

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This is for anyone who’s good with science coz I absolutely hate it. ILL BRAINLIST U AND GIVE U 5 STAR TO WHOEVER IS GOOD;) be s

marusya05 [52]

Answer:

A) Oxygen

B) Heat

Explanation:

Hope it helps

4 0

3 years ago

Read 2 more answers

Which of the following contains a nonpolar covalent bond? O2 CO NaCI HF

jasenka [17]

Answer: The nonpolar covalent bond happens in an O₂ molecule.

Explanation: Nonpolar bonds happen where there's no difference between the polarity of the atoms involved. This usually happens when the same atoms bond to each other, which explains why the O₂ molecule is the one who has this bond.

5 0

3 years ago

When heated, lithium reacts with nitrogen to form lithium nitride: 6Li(s) + N2(g) → 2Li3N(s) What is the theoretical yield of Li

anyanavicka [17]

Answer:

The % yield of the reaction = 27.5 %

Explanation:

Step 1: Data given

Mass of Li = 12.7 grams

Mass of N2 = 34.7 grams

Actual yield of Li3N = 5.85 grams

Molar mass of Lithium = 6.94 g/mol

Molar mass of N2 = 28 g/mol

Molar mass of LI3N = 34.83 g/mol

Step 2: The balanced equation:

6Li(s) + N2(g) → 2Li3N(s)

Step 3: Calculate moles of Lithium

Moles Li = mass Li / Molar mass Li

Moles Li = 12.7 grams / 6.94 g/mol

Moles Li = 1.83 moles

Step 4: Calculate moles of N2

Moles N2 = 34.7 g/ 28 g/mol

Moles N2 = 1.24 moles

Step 5: Limiting reactant

For 6 moles Li consumed, we need 1 mole of N2 to produce 2 moles of Li3N

Lithium is the limiting reactant. It will completely be consumed (1.83 moles).

N2 is in excess. There will be consumed 1.83 / 6 = 0.305 moles

There will remain 1.24 - 0.305 = 0.935 moles

Step 6: Calculate moles of Li3N

For 6 moles Li consumed, we need 1 mole of N2 to produce 2 moles of Li3N

For 1.83 moles Li, we'll have 1.83/3 = 0.61 moles of Li3N

Step 7: Calculate mass of Li3N

Mass Li3N =moles LI3N * Molar Mass LI3N

Mass Li3N = 0.610 moles * 34.83 g/mol

Mass Li3N = 21.2463 grams = Theoretical yield

Step 8: Calculate % yield

% yield = actual yield / theoretical yield

% yield = (5.85 / 21.2463)*100% = 27.5%

The % yield of the reaction = 27.5 %

8 0

3 years ago

The teacher tells your group to make a stock solution of sodium chloride, and then diluting it to

sergejj [24]

The idea here is that you need to figure out how many moles of magnesium chloride,

MgCl

, you need to have in the target solution, then use this value to determine what volume of the stock solution would contain this many moles.

As you know, molarity is defined as the number of moles of solute, which in your case is magnesium chloride, divided by liters of solution.

So, how many moles of magnesium chloride must be present in the target solution?

⇒

⋅

0.158 M

⋅

250.0

⋅

−

0.0395 moles MgCl

Now determine what volume of the target solution would contain this many moles of magnesium chloride

⇒

0.0395

moles

3.15

moles

0.01254 L

Rounded to three sig figs and expressed in mililiters, the volume will be

12.5 mL

So, to prepare your target solution, use a

12.5-mL

sample of the stock solution and add enough water to make the volume of the total solution equal to

250.0 mL

This is equivalent to diluting the

12.5-mL

sample of the stock solution by a dilution factor of

3 0

3 years ago

Which substances corrode copper?

DiKsa [7]

The presence of oxidizing acids; heavy-metal salts, sulfur, and ammonia; and a number of sulfur and ammonia compounds can cause corrosion to set in. Water that comes from a well is much more likely to contain these materials and put copper lines in jeopardy—but it can occur in the civic water system as well.

Copper corrodes at insignificant rates when used in areas with unpolluted air, non-oxidizing acids, and water. However, it happens more rapidly with the presence of road salt, ammonia, sulfur, oxidizing acids

Acidic substances react with the surface of copper, causing it to tarnish and corrode almost instantly. This corrosion is highly soluble, leading to the presence of toxic copper salts in the food. This is why it is not recommended to use copper vessels for foods high in acidity, such as milk, wine, or vinegar.

4 0

3 years ago