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2 years ago

Help me with this science question on the middle one..

Chemistry

1 answer:

viktelen [127]2 years ago

8 0

Networks of feeding relationships is correct

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I need this by today it’s due 4-24-20

dybincka [34]

Answer:

Question 6

Plants use flowers to absorb photsynthese

4 0

3 years ago

luminum and oxygen react according to the following equation: 4Al(s) +3O2(g) --> 2Al2O3(s) What mass of Al2O3, in grams, can

Slav-nsk [51]

Answer: 8.7 grams

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:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{4.6g}{27g/mol}=0.17moles$

$4Al(s)+3O_2(g)\rightarrow 2Al_2O_3(s)$

As oxygen is in excess, Aluminium is the limiting reagent and limits the formation of products.

According to stoichiometry:

4 moles of aluminium give = 2 moles of $Al_2O_3(s)$

Thus 0.17 moles of aluminium give= $\frac{2}{4}\times 0.17=0.085mol$

Mass of $Al_2O_3=moles\times {\text {molar mass}}=0.085\times 102g/mol=8.7g$

Thus the mass of $Al_2O_3(s)$ is 8.7 grams

8 0

2 years ago

Needed help plzzz on this chemistry homework.

mrs_skeptik [129]

Hertz is units for frequency. (waves per second)
wavelength = speed/frequency

if you're given the speed use that to calculate, if not then you can probably assume it's a wave of light and use the speed of light (3x10^8 m/s) to calculate.

wavelength = (3x10^8)/(1.28x10^17)
= 0.000000002 m
= 2.34 nm

5 0

3 years ago

A sample containing 16.93 metal pellets is poured into a graduated cylinder containing 11.2 of water, causing the water level in

mixer [17]

Answer:

<h3>The answer is 1.99 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 16.93 g

volume = final volume of water - initial volume of water

volume = 19.7 - 11.2 = 8.5 mL

We have

$density = \frac{16.93}{8.5} \\ = 1.9917647058...$

We have the final answer as

Hope this helps you

7 0

3 years ago

I need help!! Following measurements

Anna71 [15]

I am so sorry I do not know but I need to answer a question in order to ask one I hope u pass:))

5 0

2 years ago