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3 years ago

Why are atomic masses on the Periodic Table written in decimals when they are based on mass numbers that can be whole numbers?

1 answer:

8 0

To allow for equations and problems in chemistry to be as precise as possible. When experiments are conducted, and even if the number is the slightest bit off, the problem or experiment could be impacted very negatively. It allows for complete accuracy to ensure nothing goes wrong, since chemistry is very touchy and risky when dealing with extremely unsafe elements.

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What is the net force of the plane

ExtremeBDS [4]

Answer: The difference between the opposing forces; lift minus weight, or thrust minus drag.

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3 years ago

What does the large number in front of<br> the molecule represent?

madam [21]

A large number in front of a compound designates how many units there are of that compound. Parentheses can be used to designate a special structure, where other molecules are attached to the larger, complex molecule.

4 0

3 years ago

Read 2 more answers

Determine the [H3O+] in a 0.265 M HClO solution. The Ka of HClO is 2.9 × 10-8.

dexar [7]

8.8 × 10-5 M is the [H3O+] concentration in 0.265 M HClO solution.

Explanation:

HClO is a weak acid and does not completely dissociate in water as ions.

the equation of dissociation can be written and ice table to be formed.

HClO +H2O ⇒ ClO- + H3O+

I 0.265 0 0

C -x +x +x

E 0.265-x +x +x

Now applying the equation of Ka, where Ka is given as 2.9 × 10-8.

Ka = $\frac{[ClO-][H3O+]}{[HClO]}$

2.9 × 10^-8 = $\frac{[x] [x]}{[0.265-x]}$

$x^{2}$ = 7.698 x $10^{-9}$

x = 8.8 × 10-5 M

The hydronium ion concentration is 8.8 × 10-5 M in 0.265 M solution of HClO.

8 0

3 years ago

when carbon is burned in the air, it reacts with oxygen to form carbon dioxide. when 22.8 g of carbon were burned in the presenc

OverLord2011 [107]

Answer:

So there is83.6g CO2 produced

Explanation:

Burning carbon with air has the following equation

C + O2 → CO2

For 1 mol Carbon, we have 1 mol O2 and 1 mol CO2

Step 2: Calculating moles

mole C = 22.8g / 12g/mole

Mole C = 1.9 mole

1.9 mole C will completely react

Since for each mole C there is 1 mole O2 and 1 mole CO2

This means there will also react 1.9 mole of 02, to be formed 1.9 mole of CO2

mole CO2 = mass CO2 / Molar mass CO2

mass CO2 = 1.9 mole CO2 * 44g/mole =<u>83.6g CO2</u>

In this reaction 18.2 g of O2 remained unreacted

we can control this: 79g - 18.2 g = 60.8g

1.9 mole * 32g/mol = 60.8g

So there is83.6g CO2 produced

4 0

3 years ago

Scientists need special tools to work in the laboratory. These tools are known as___________

inessss [21]

Instruments

The specific type of instruments depends on the type of laboratory that you're working in: some labs for example use electron microscopes, others use mass spectrophotometers, others use multiplex biochemical analyzers, etc. But very broadly, the specialized tools we use in the laboratory are usually referred to as "instruments"

3 0

3 years ago