# A5.5 g sample of a substance contains only carbon and oxygen. carbon makes up 35% of the mass of the

###### Question:

((100 - 35)/100) x 5.5 grams =

100 - 35/100 x 5.5 grams =

100 - (35/100) x 5.5 grams =

recall that to calculate a percent of an amount in grams means you have to convert the percent to a number and multiply by the amount in grams. for example, 50% means 50 out of 100, or 50 hundredths. so 50% of 10 grams is 0.50 times 10 grams. you need to take 0.50 and multiply it by 10 grams to determine 50% of 10 grams is 5.0. (50% and 10 grams are examples and not numbers for this problem.)

## Answers

((100-35)/100) x 5.5grams=3.575grams of oxygen

Explanation:

Since ha sample contains 35% carbon which means (100-35)=65% is oxygen in the sample. In order to calculate the mass of oxygen in the sample we have to find the 65% of 5.5g which means we have to multiply 65/100=0.65 with 5.5g i.e 0.65*5.5. so the mathematical expression we use will be:

((100-35)/100) x 5.5grams=3.575grams of oxygen

5.5g times ( 1-.35 )

((100−35)/100)×5.5 grams =

Step-by-step explanation:

There are several ways you can do this. The equation above shows you subtracting 35% from 100% before you convert the result to a fraction. That is an appropriate expression for solving the problem.

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The other offered choices do not respect either the order of operations or the units of the problem. (The first and third choices are the same--both wrong.)

The correct answer is option (1).

Explanation:

Mass of the sample = 5.5 g

Percentage of carbon in sample = 35 %

Percentage of oxygen in sample = 100% - 35%

[tex]\%=\frac{\text{Mass of the element in the sample}}{\text{Mass of sample}}\times 100[/tex]

Mass of carbon in a sample: (35%) of 5.5 g

[tex]\frac{35}{100}\times 5.5 g=1.925 g[/tex]

Mass of oxygen in a sample: (100%-35%) of 5.5 g

[tex]\frac{100-35}{100}\times 5.5 g=3.575 g[/tex]

We have been given the condition that carbon makes up 35% of the mass of the substance and the rest is made up of oxygen. With this, it can be concluded that 65% of the substance is made up of oxygen. If we let x be the mass of oxygen in the substance, the operation that would best represent the scenario is,

x = (0.65)(5.5 g)

x = 3.575 g

Mass percentage is one way of representing the concentration of an element in a compound or a component in a mixture. Mass percentage is calculated as the mass of a component divided by the total mass of the mixture. We calculate as follows:

Percent O2 = 100 - 35 = 65%

Mass of oxygen = 5.5 x 0.65 = 3.575 g O2