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2 years ago

Why do substances burn with or without flame?

2 answers:

8 0

It burns with flames because of the presence of oxygen and without flame because when there is every tendency that dry substances can burn due to intense sunlight on it especially a Sulphuric substance

Gala2k [10]2 years ago

7 0

Flame (fire) is the effect of a chemical reaction that produces visible light and heat. The chemical reaction is going on in the substance being burned.. Thats why coals glow and flames seem to leap into the air.

<span>If your reaction does not have a flame, then either it is not producing visible light or the reaction does not occur in the air above the substance.</span>

You might be interested in

Science always begins with what?

tiny-mole [99]

Step 7- Communicate. Present/share your results. Replicate.

Step 1- Question.

Step 2-Research.

Step 3-Hypothesis.

Step 4-Experiment.

Step 5-Observations.

Step 6-Results/Conclusion.

3 0

2 years ago

During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.

Monica [59]

Answer:

0.74 grams of methane

Explanation:

The balanced equation of the combustion reaction of methane with oxygen is:

CH₄ + 2 O₂ → CO₂ + 2 H₂O

it is clear that 1 mol of CH₄ reacts with 2 mol of O₂.

firstly, we need to calculate the number of moles of both

for CH₄:

number of moles = mass / molar mass = (3.00 g) / (16.00 g/mol) = 0.1875 mol.

for O₂:

number of moles = mass / molar mass = (9.00 g) / (32.00 g/mol) = 0.2812 mol.

it is clear that O₂ is the limiting reactant and methane will leftover.

using cross multiplication

1 mol of CH₄ needs → 2 mol of O₂

??? mol of CH₄ needs → 0.2812 mol of O₂

∴ the number of mol of CH₄ needed = (0.2812 * 1) / 2 = 0.1406 mol

so 0.14 mol will react and the remaining CH₄

mol of CH₄ left over = 0.1875 -0.1406 = 0.0469 mol

now we convert moles into grams

mass of CH₄ left over = no. of mol of CH₄ left over * molar mass

= 0.0469 mol * 16 g/mol = 0.7504 g

So, the right choice is 0.74 grams of methane

3 0

2 years ago

Help please please please!

LenaWriter [7]

Answer:

I say the second one, im not rlly sure tho

Explanation:

5 0

2 years ago

4. How many grams of ammonium carbonate are needed to decompose in order to produce

Thepotemich [5.8K]

Answer:

14.23g of (NH4)2CO3

Explanation:

We'll begin by writing the balanced equation for the reaction.

(NH4)2CO3 –> (NH4)2O + CO2

Next,, we shall determine the mass of (NH4)2CO3 that decomposed and the mass of CO2 produced from the balanced equation. This is illustrated below:

Molar mass of (NH4)2CO3 = 2[14+(4x1)] + 12 + (16x3)

= 2[14 +4] + 12 + 48

= 2[18] + 60 = 96g/mol

Mass of (NH4)2CO3 from the balanced equation = 1 x 96 = 96g

Molar mass of CO2 = 12 + (2x16) = 44g/mol

Mass of CO2 from the balanced equation = 1 x 44 = 44g.

Summary:

From the balanced equation above,

96g of (NH4)2CO3 decomposed to produce 44g of CO2.

Finally, we can determine the mass of (NH4)2CO3 that decomposed to produce 6.52g of CO2 as follow:

From the balanced equation above,

96g of (NH4)2CO3 decomposed to produce 44g of CO2.

Therefore, Xg of (NH4)2CO3 will decompose to produce 6.52g of CO2 i.e

Xg of (NH4)2CO3 = (96 x 6.52)/44

Xg of (NH4)2CO3 = 14.23g

Therefore, 14.23g of (NH4)2CO3 is needed to produce 6.52g of CO2.

4 0

3 years ago

The sum of the protons and neutrons in an atom is called the atomic number <br> True or False

olganol [36]

It is false, the atomic number is the number of protons and/or electrons in an atom on an element.

3 0

2 years ago