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3 years ago

Convert 1.5 km to millimeters, and express the result in scientific notation.

Chemistry

1 answer:

Grace [21]3 years ago

7 0

The answer is 1.5e+6. Hope this helped!

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What is the formula for an alkene containing six carbon atoms?

Charra [1.4K]

Answer:

Explanation:

Cyclohexane is a cycloalkane with the molecular formula C₆H₁₂. Cyclohexane is non-polar.

3 0

3 years ago

When the temperature in a room increases from 25°C to 33°C, changes from a solid to a liquid.

mr Goodwill [35]

Answer:

true

Explanation:

Because ice melts if the temperature increasese

8 0

3 years ago

A 5.000 g mixture contains strontium nitrate and potassium bromide. Excess lead(II) nitrate solution is added to precipitate out

scZoUnD [109]

Answer: The mass percent of potassium bromide in the mixture is 9.996%

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For lead (II) bromide:

Given mass of lead (II) bromide = 0.7822 g

Molar mass of lead (II) bromide = 367 g/mol

Putting values in equation 1, we get:

$\text{Moles of lead (II) bromide}=\frac{0.7822g}{367g/mol}=0.0021mol$

The chemical equation for the reaction of lead (II) nitrate and potassium bromide follows:

$2KBr+Pb(NO_3)_2\rightarrow PbBr_2+2KNO_3$

By Stoichiometry of the reaction:

1 mole of lead (II) bromide is produced from 2 moles of potassium bromide

So, 0.0021 moles of lead (II) bromide will be produced from = $\frac{2}{1}\times 0.0021=0.0042mol$ of potassium bromide

Now, calculating the mass of potassium bromide by using equation 1, we get:

Molar mass of KBr = 119 g/mol

Moles of KBr = 0.0042 moles

Putting values in equation 1, we get:

$0.0042mol=\frac{\text{Mass of KBr}}{119g/mol}\\\\\text{Mass of KBr}=0.4998g$

To calculate the percentage composition of KBr in the mixture, we use the equation:

$\%\text{ composition of KBr}=\frac{\text{Mass of KBr}}{\text{Mass of mixture}}\times 100$

Mass of mixture = 5.000 g

Mass of KBr = 0.4998 g

Putting values in above equation, we get:

$\%\text{ composition of KBr}=\frac{0.4998g}{5.000g}\times 100=9.996\%$

Hence, the percent by mass of KBr in the mixture is 9.996 %

5 0

3 years ago

First law of Thermodynamics

guapka [62]

Answer:

Thermal energy is taken from heat sink in higher temperature. A thermal power machine does mechanical energy using part of the heat.

Part of heat taken are given in cold reservoir in lower temperature

Explanation:

7 0

3 years ago

C-12 has 6 protons. how many neutrons does c-13 have? select one:

lina2011 [118]

I think it's Letter c.13 if I'm not mistaken

3 0

3 years ago