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3 years ago

2.

Chemistry

1 answer:

Arturiano [62]3 years ago

6 0

Answer:

they are producers and they have means to keep themselves warm

Explanation:

I took test and saw answer.

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Which law represents a balanced chemical equation?

Nastasia [14]

Answer:

Law of Conservation of Mass

Explanation:

Balancing chemical equation means that the amount of moles of one atom on side must match the other, which makes sure that no atoms are created nor destroyed in the reaction process.

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3 years ago

In a lab experiment, john uses a mesh to separate soil particles from water. Which technique of separation is he using

blondinia [14]

The Filtration techique

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3 years ago

How are the properties of Metalloids different from Metals and Nonmetals?

konstantin123 [22]

Metalloids show both metal and non metal properties

4 0

4 years ago

Considering that the mantle is 44.8% oxygen and 21.5% silicon by mass, calculate the mole ratio of oxygen atoms to silicon atoms

horrorfan [7]

The mantle has a mass of around $4.278 X 10 ^2^4 kg$ that is around 68.4% of earth's mass.

So to calculate moles we need to first find out the mass of oxygen and silicon present in mantle. It is given that oxygen is 44.8% by mass in mantle and 21.5% by mass in mantle, therefore to calculate its mass, we need to use $\text{mass percentage }=\frac{\text{mole of solute}}{\text{mass of solution}}\times100$

Now, to calculate mass percentage of oxygen

$44.8 =\frac{x}{4.278X10^2^4kg}\times100$

$x= 191.65\times10^2^2kg$

Similarly the mass of silicon can be calculated

$21.5 =\frac{x}{4.278X10^2^4kg}\times100$

$x=91.977\times10^2^2kg$

Now, the moles of any substance is calculated by

$\text{moles}= \frac{\text{given mass}}{\text{molar mass}}$

$\text{moles of oxygen}= \frac{191.65\times10^2^2kg}{2.6566962\times10^-^2^6kg}$

where, mass of oxygen in kilograms is $2.6566962\times10^-^2^6kg$

So, $\text{moles of oxygen}=72.1384\times10^4^8\text{moles of O}$

Similarly $\text{moles of silicon}= \frac{91.977\times10^2^2kg}{4.663\times10^-^2^6kg}$

$\text{moles of silicon}=19.724\times10^4^8\text{moles of Si}$

Now, to calculate mole ratio we need to divide every moles to the lowest calculated mole that is the moles of Si and round it off to the nearest whole number.

$\text{mole ratio of oxygen}= \frac{72.138\times10^4^8kg}{19.724\times10^4^8kg}$

$=3.65\approx 4$

$\text{mole ratio of Silicon}=\frac{19.724\times10^4^8}{19.724\times10^4^8}$

$=1$

$\text{Mole ratio of Oxygen : Mole ratio of Silicon} = 4:1$

6 0

4 years ago

Read 2 more answers

Which of the following molecules or ions is polar? (20 POINTS)

taurus [48]

For NO3- molecule(fig.1)

1. Bonds are created between elements with different electronegativity, most bonds would be polar. Bonds in NO3 are polar.

2. In the geometry of the molecule bond polarities cancel out each other (since it is a vector) so NO3- ion molecule is non polar

3. Nitrate (NO3-)ion geometry would be trigonal planar

For CCl4 molecule(fig.2)

1. Bonds are created between elements with different electronegativity, most bonds would be polar. Bonds in CCl4 are polar.

2. It is a completely symmetrical molecule.

3.Carbon is the centre of CCl4 have four covalent bonds and it has no lone pairs. They are all equidistant the C-Cl bond polarities cancel out. So CCl4 molecule is non polar

For NH3 molecule(fig.3)

1. Bonds are created between elements with different electronegativity, most bonds would be polar. Bonds in NH3 molecule are polar.

2. it has a pyramidal structure.

3. the individual N-H bond dipoles don't cancel out. This dipole moment for the molecule indicates that NH3 is a polar molecule

For SF6 molecule(fig.4)

1.F is more electronegative than S. So the bonds are polar.

2. The symmetry of the molecule is symmetrical so that the dipole moments of bonds cancel correspond so the molecule is non-polar.

3. it has octahedral structure

3 0

4 years ago