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3 years ago

Which of these is an example of chemical change

Chemistry

1 answer:

Margaret [11]3 years ago

8 0

Answer:

Burning, cooking, rusting and rotting are examples of chemical changes.

Explanation:

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To conclude through reasoning from something known or assumed is to ___.

sp2606 [1]

Is it to hypothesize?

6 0

3 years ago

Read 2 more answers

Melatonin has the chemical formula C13H16N2O2. Less than 10 milligrams(0.01g) Convert the melatonin to moles

oee [108]

Answer: There are 0.000043 moles of melatonin.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

given mass = 10 mg = 0.01 g

molar mass of $C_{13}H_{16}N_2O_2$ = 232.28 g

${\text {moles of melatonin}}=\frac{0.01g}{232.28g/mol}=0.000043moles$

Thus there are 0.000043 moles of melatonin

6 0

3 years ago

Ricardo is working on a refrigeration system and needs to know the fluid pressure of a water tank. He knows that the tank is 12

hjlf

Answer:

I also have this question but see the 69 page of ur question book

8 0

2 years ago

0.446 g of hydrogen gas fills a 5.0 L bag determine the density of hydrogen

Oduvanchick [21]

The density of hydrogen : ρ = 0.0892 g/L

<h3>Further explanation</h3>

Given

mass of Hydrogen : 0.446 g

Volume = 5 L

Required

The density

Solution

Density is a quantity derived from the mass and volume

Density is the ratio of mass per unit volume

The unit of density can be expressed in g/cm³, kg/m³, or g/L

Density formula:

$\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}$

Input the value :

ρ = m : V

ρ = 0.446 g : 5 L

ρ = 0.0892 g/L

5 0

3 years ago

Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of

dsp73

The first thing we need to do here is to recognize the unit of molarity and the units of the given percentage of nitric acid.

Molarity is mol HNO3 / L of solution. This is our aim

The given percentage is 0.68 g HNO3/ g solution

multiplying this with density to convert g solution into mL solution and dividing with the molecular weight of HNO3 (63 g/mol) to convert g HNO3 to mol. Therefore we obtain

0.016 mol/ mL or 16.23 mol/ L (M)

6 0

3 years ago