All categories

3 years ago

Why does cold air sink

2 answers:

7 0

The opposite is true for cold air<span>. It is more dense because the molecules are closer together and they are closer together because the bonds are absorbing less energy and therefore do not move as much.</span>

Maru [420]3 years ago

3 0

The absorted energy makes molecules in air move and expand therefore decreasing the airs density..

You might be interested in

Which source should be avoided when conducting scientific research? encyclopedias

WINSTONCH [101]

Wikipedia
Blogs from random people

3 0

3 years ago

Read 2 more answers

Britney added 0.05 moles of copper(II) nitrate solution to 0.1 moles of sodium hydroxide solution and

Rama09 [41]

The percent yield of copper hydroxide is 84%

<h3>Stoichiometry</h3>

From the question, we are to determine the percent yield of copper hydroxide

First, we will determine the theoretical mass

From the given balanced chemical equation, we have

Cu(NO₃)₂ + 2NaOH -- Cu(OH)₂ + 2NaNO₃

This means,

1 mole of copper(II) nitrate reacts with 2 moles of sodium hydroxide to produce 1 mole of copper hydroxide

Therefore,
0.05 mole of copper(II) nitrate reacts with 0.1 mole of sodium hydroxide to produce 0.05 mole of copper hydroxide

The theoretical number of moles of copper hydroxide that is produced is 0.05 mole

Now, for the theoretical mass

Using the formula,

Mass = Number of moles × Molar mass

Molar mass of copper hydroxide = 97.56 g/mol

Then,

Theoretical mass = 0.05 × 97.56

Theoretical mass of copper of hydroxide produced is = 4.878 g

Now, for the percent yield of copper hydroxide

Percent yield is given by the formula,

$Percent\ yield = \frac{Actual\ yield}{Theoretical\ yield} \times 100\%$

Then,

$Percent\ yield\ of\ copper\ hydroxide= \frac{4.1}{4.878}\times 100\%$

$Percent\ yield\ of\ copper\ hydroxide= 84\%$

Hence, the percent yield of copper hydroxide is 84%.

Learn more on Stoichiometry here: brainly.com/question/9372758

7 0

3 years ago

Ultraviolet radiation has a frequency of 6.8×1015 Hz. What is the energy associated with this frequency?

stellarik [79]

Use Planck's equation (E=hv) to solve. where <span>frequency (v) of ultrviolet radiation is 6.8 × 1015 1/s. </span><span> </span>The variable h is a constant equal to 6.63 × 10-34 J·s
E= <span>(6.8 × 1015 1/s)x(</span>6.63 × 10-34 J·s)

5 0

4 years ago

How do microwaves cook food? A) by using electromagnetic waves and the process of radiation B) by using forced hot air currents

Makovka662 [10]

I'm pretty sure the answer is letter A.)

6 0

3 years ago

Read 2 more answers

At high temperatures phosphine (PH_3) dissociates into phosphorus and hydrogen by the following reaction: 4PH3 rightarrow P_4 +

Alex_Xolod [135]

Answer:a)p4=0.75mol

H2=4.5mol

B)PH3=1×10^7mole

P4=0.25×10^7mole

H2=1.5×10^7mole

Time taken for 3mol of phosphine to react is 54 ×10^7s

Explanation:From the balanced chemical equation

4PH3____P4+6H2

From Gay lussac law ,when gases combines

,They do so in a ratio which bear a simple ratio with their products,if gases.

So it means from the equation above

4 mol of PH3 will form 1mol of P4 and 6 mol of H2

Meaning that if 4mol of PH3 gives 1mol of P4

Then 3mol of PH3 will give 1/4 mol or 0.75 mol of P4 .

In the same vein,3mol of PH3 will give 6×3/4 mol of H2= 4.5 Mol of H2

B) molar concentration =mole/volume

Meaning mole=molar concentration ×volume

Molar concentration is given as 5Km/m^3=5000mol/m^3

Volume=2L =2×1000=2000m^3

Nos of moles=5000×2000=10^7moles

So for P4,nos of moles =1/4×10^7=0.25×10^7

ForH2 ,6/4 ×10^7=1.5×10^7 moles

Rate= volume/time

Time taken for reaction will be volume/rate=2000/3.715×10^6

=54×10^7s

5 0

3 years ago