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2 years ago

Burning a piece of wood in fire can be best described as a

Chemistry

1 answer:

inna [77]2 years ago

7 0

Answer:

Chemical Change

Explanation:

A chemical change is when something is turned into a new substances.

In this example the wood is being turned into ash.

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A new grill has a mass of 30.0 kg. you put 1.5 kg of charcoal in the grill. you burn all the charcoal and the grill has a mass o

atroni [7]

The reaction for burning of charcoal or complete combustion is as follows:

$C(s)+O_{2}(g)\rightarrow CO_{2}(g)$

From the above balanced reaction, 1 mole of carbon releases 1 mole of $CO_{2}$ gas.

Converting mass of charcoal into moles as follows:

$n=\frac{m}{M}$

Molar mass of pure carbon is 12 g/mol thus,

$n=\frac{1.5\times 10^{3} g}{12 g/mol}=125mol$

The same moles of $CO_{2}$ is released. Converting these moles into mass as follows:

m=n×M

Molar mass of $CO_{2}$ is 44 g/mol thus,

$m=125mol\times 44 g/mol=5.5\times 10^{3}g$

Converting mass into kg,

$1g=10^{-3}kg$

Thus, total mass of gas released is 5.5 kg.

7 0

3 years ago

White phosphorus is composed of tetrahedral molecules of P4 in which every P atom is connected to three other P atoms. In the Le

Dmitrij [34]

Answer:

In the Lewis structure of P4 there are 6 bonding pairs and 4 lone pairs of electrons.

Explanation:

The structure of tetrahedral molecule of P4 is provided below.

Each phosphorus atom has 5 valence electrons out of which 3 electrons involve in bonding and the rest 2 electrons exist as a lone pair that does not involve in bonding.Hence each phosphorus atom has one lone pair.In P4 molecule there are phosphorus atoms and hence 4 lone pairs in total.

As you can see in the figure, each phosphorus atom is bonded to the other three atoms.A bond is formed when two atoms share one electron each and the pair is called bonding pair.

From the figure we can see that there are 6 bonds in total.Each bond consist of one bonding pair of electrons and hence in total there are 6 bonding pairs of electrons.

Hence in a P4 molecule there are six bonding pairs and 4 lone pairs of electrons.

4 0

3 years ago

Balanced nuclear equation forces the alpha decay Po-210

Serjik [45]

Answer:

$_{84}^{210}\text{Po} \longrightarrow \, _{82}^{206}\text{Pb} \, + \, _{2}^{4}\text{He}$

Explanation:

Your unbalanced nuclear equation is:

$_{84}^{210}\text{Po} \longrightarrow \, _{x}^{y}\text{Z} + \, _{2}^{4}\text{He}$

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.

Then

84 = x + 2, so x = 84 - 2 = 82

210 = y + 4, so y = 210 - 4 = 206

Element 82 is lead, so the nuclear equation becomes

$_{84}^{210}\text{Po} \longrightarrow \, _{82}^{206}\text{Pb} \, + \, _{2}^{4}\text{He}$

8 0

3 years ago

Are plant cells affected when water is scarce

boyakko [2]

<span>Water is vital to the existence of plant life. Not only do plants use it to keep their cells from drying out, but they need water to move nutrients and raw materials throughout their systems to areas where photosynthesis and seed production take place. When water stress occurs, whether caused by drought or root impairment, many invisible processes are affected.</span>

5 0

3 years ago

The following reaction is found to be at equilibrium at 25 celcius: 2SO3--->O2 + 2SO2 + 198kJ/mol. If the value for Kc at 25

kondaur [170]

Answer:

D.) Products are weakly favored

Explanation:

For the reaction:

2SO₃ ⇄ O₂ + 2SO₂ + 198kJ/mol

The kc is defined as:

kc = [O₂] [SO₂]² / [SO₃]²

As the kc is 8,1:

8,1 [SO₃]² = [O₂] [SO₂]²

The products are favored 8,1 times. This is a weakly favored because the usual kc are in the order of 1x10⁴. Thus, right answer is:

D.) Products are weakly favored

I hope it helps!

4 0

4 years ago