Is this a compound, element, or mixture????

How does the jet stream influence weather?

LiRa [457]

Jets streams play a key role in determining the weather because they usually separate colder air and warmer air.

4 0

2 years ago

What is the coefficient of Ca(OH)2 in the equation Ca(OH)2 + HNO3 → Ca(NO3)2 + H2O when balanced using the smallest possible coe

Vikentia [17]

Answer:

The coefficient of Ca(OH)2 is 1

Explanation:

Step 1: unbalanced equation

Ca(OH)2 + HNO3 → Ca(NO3)2 + H2O

Step 2: Balancing the equation

On the right side we have 2x N (in Ca(NO3)2 ) and 1x N on the left side (in HNO3). To balance the amount of N on both sides, we have to multiply HNO3 by 2.

Ca(OH)2 + 2HNO3 → Ca(NO3)2 + H2O

On the left side we have 4x H (2xH in Ca(OH)2 and 2x H in HNO3), on the right side we have 2x H (in H2O). To balance the amount of H on both sides, we have to multiply H2O on the right side, by 2.

Now the equationis balanced.

Ca(OH)2 + 2HNO3 = Ca(NO3)2 + 2H2O

The coefficient of Ca(OH)2 is 1

4 0

2 years ago

A pharmacist wishes to strengthen a mixture from 10%alcohol to 30% alcohol. How much pure alcohol should be added to 7 liters of

Tomtit [17]

Answer:

2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.

Explanation:

Suppose x is the number of litres added to the 10% mixture than the quantity of new mixture is given as below

$n_{old}=7$ litres
$n_{new}=7+x$ litres

Also the quantity of alcohol is given as

$q_{old}=10 \% \, of \, 7 \, litres =0.7$

$q_{added}=x$

$q_{new}= 30 \% \,of \,new\, quantity = 0.3(7+x)$

Now the equation is as

$q_{old}+q_{added}=q_{new}\\0.7+x=0.3(7+x)\\0.7+x=2.1+0.3x\\x-0.3x=2.1-0.7\\0.7x=1.4\\x=2 \, litres$

So 2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.

8 0

3 years ago

In an equimolar mixture of o2 and n2, are the mass fractions equal?

nika2105 [10]

Answer:

No

Explanation:

The mass fraction is defined as:

$w_{i}=\frac{m_{i} }{m_{t} }$

where:

wi: mass fraction of the substance i
mi: mass of the substance i
mt: total mass of the system

<u><em>The mass fraction of two substances (A and B), will be the same, ONLY if the mass of the substance A (mA) is the same as the mass of the substance B (mB).</em></u>

An equimolar mixutre of O2 and N2 has the same amount of moles of oxygen and nitrogen, just to give an example let's say that the system has 1 mole of O2 and 1 mole of N2. Then using the molecuar weigth of each of them we can calculate the mass:

mA= 1 mole of O2 * 16 g/1mol = 16 g

mB=1 mole of N2 *28 g/1mol=28 g

As mA≠mB then the mass fractions are not equal, so the answear is NO.

4 0

3 years ago

When does the electron release the greatest amount of energry as it moves from one level to another?

gayaneshka [121]

I can't see the picture, but in general, I believe it is in dropping from the first energy level above the ground state, to the ground state.

6 0

2 years ago