Solid carbon reacts with oxygen gas to form carbon dioxide gas.
The balanced chemical equation for this reaction:
When sand and water are mixed in equal or unequal proportions, a heterogeneous mixture results.This mixture can be separated by following the processes of:
1)Sedimentation
2)Decantation
The mixture of sand and water is taken in a beaker and allowed to stand for sometime. The sand being heavier than water and insoluble in water settles at the bottom of the beaker. Next process is decantation.

Separate sand from water – Decantation
A process by which the clear liquid above the sediment is slowly separated by pouring out the liquid into another container. The clear liquid is called “supernatent” liquid.

Thus the separation of the mixture of sand and water can be achieved in two steps viz sedimentation and decantation.
Separate sand from water – Significance
The separation of a mixture does not involve any chemical reactions nor does it require any energy input.
The separation of a mixture involves only physical methods and the constituents can be recovered from the mixture without destroying any of the properties of either of the constituents.
The above methods of separation of sand from water support these observations. The methods of sedimentation and decantation are especially useful when the particle size of the insoluble impurity (sand in this case) is sufficiently big as to be isolated from the mixture without affecting the properties of either constituent.
These are some of the most common methods used in almost every house hold for many years to isolate the insoluble large particle sized impurities from water or from any solvent.
However the only drawback of this method is that the supernatant liquid is not obtained in a very pure form and the insoluble impurity has to be dried if it has to be obtained in the pure dry state.
The principle behind the sedimentation is that the insoluble impurities being heavier can easily settle down under the influence of gravity.
The importance of this process lies in the work of a river as the river flows on the surface of the earth. As the river corrodes the rocks and carries the broken pieces along its path downhill and flows through the plains the larger pieces of the rocks get deposited along the river bed and while it flows through the plains the finer particles get deposited in the river bed and the supernatant water with the soluble salts are carried away to the sea. The final result is large deposits of silt on the plains and the rich deposit
The appropriate scatter plot that depicts the correct division for using Divide center to draw trend line is the plot D.
<h3>What are Scatter plots?</h3>
Scatter plots are used to show how much one variable affects another by plotting data points on a horizontal and vertical axis. Each row in the data table is represented by a marker, the position of which is determined by the values of the columns set on the X and Y axes. Scatter plots are graphs that show the relationship of two variables in a data set. It is a two-dimensional plane or a Cartesian system that represents data points.
In order to draw a trend line correctly, divide the points using the divide center method. The dividing vertical line must be drawn at the midpoint (a position where the number of data points to the left and right of the vertical line is equal).
Only option D has a vertical line dividing the 6 data points into two equal portions when the options are evaluated based on this condition.
The diagram is attached.
Learn more about scatter plot on:
brainly.com/question/24307855
#SPJ1
A COMBUSTION reaction occur when a substance ...........................................
Combustion reaction is also known as burning. It occurs when an hydrocarbon react with oxygen to yield carbon dioxide, water and energy in the form of light and heat. Combustion reaction can not take place in the absence of oxygen.
Moles of helium is required to blow up a balloon to 87.1 liters at 74 C and 3.5 atm is 021.65 mole
Mole is the unit of amount of substances of specified elementary entities
According to the ideal gas law he number of moles of a gas n can be calculated knowing the partial pressure of a gas p in a container with a volume V at an absolute temperature T from the equation
n =pV/RT
Here given data is volume = 87.1 liters
Temperature = 74 °C means 347.15 k
Pressure = 3.5 atm
R = 0.0821
Putting this value in ideal gas equation then
n =pV/RT
n = 3.5 atm×87.1 liters / 0.0821 ×347.15 k
n = 021.65 mole
Moles of helium is required to blow up a balloon to 87.1 liters at 74 C and 3.5 atm is 021.65 mole
Know more about mole of helium
brainly.com/question/23365554
#SPJ1