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Norma-Jean [14]

2 years ago

15

A green powder was placed into a beaker of water. After it was stirred the water looked cloudy and lumps of powder could still b

e seen. Has a solution been formed? Explain your answer?

1 answer:

sukhopar [10]2 years ago

7 0

Answer:

it make poisionus police come and took away

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i need help with these. its balancing. the blank spaces are where u put the numbers. and the stuff on the sidd is how u show wor

zlopas [31]

7. 1,2,2,2
8. 4,3,1
9. 1,4,1,2
10. 3,4,1,4

7 0

2 years ago

How many milliliters of 1.50 M magnesium sulfate soulution is required to supply 2.50 mole of this salt?

arsen [322]

Answer:

1670 ml

Explanation:

molarity x Volume (Liters) = moles => Volume (Liters) = moles/Molarity

Volume needed = 2.50mol/1.50M = 1.67 Liters = 1670 ml.

3 0

3 years ago

How many protons, neutrons, and electrons does a magnesium atom with a mass number of 25 contain?

guapka [62]

Protons: 12
Neutrons: 13
<span>Electrons: 12</span>

4 0

3 years ago

Three kilograms of steam is contained in a horizontal, frictionless piston and the cylinder is heated at a constant pressure of

lakkis [162]

Answer:

Final temperature: 659.8ºC

Expansion work: 3*75=225 kJ

Internal energy change: 275 kJ

Explanation:

First, considering both initial and final states, write the energy balance:

$U_{2}-U_{1}=Q-W$

Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:

$dw=Pdv$

The pressure is constant, so: $w=P(v_{2}-v_{1} )=0.5*100*1.5=75\frac{kJ}{kg}$ (There is a multiplication by 100 due to the conversion of bar to kPa)

So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):

$U_{2}-U_{1}=500-(3*75)=275kJ$

On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:

$P_{1}V_{1}=nRT_{1}$

$P_{2}V_{2}=nRT_{2}\\V_{2}=2.5V_{1}\\P_{2}=P_{1}\\2.5P_{1}V_{1}=nRT_{2}$

Subtracting the first from the second:

$1.5P_{1}V_{1}=nR(T_{2}-T_{1})$

Isolating $T_{2}$ :

$T_{2}=T_{1}+\frac{1.5P_{1}V_{1}}{nR}$

Assuming that it is water steam, n=0.1666 kmol

$V_{1}=\frac{nRT_{1}}{P_{1}}=\frac{8.314*0.1666*373.15}{500} =1.034m^{3}$

$T_{2}=100+\frac{1.5*500*1.034}{0.1666*8.314}=659.76$ ºC

7 0

3 years ago

(a) Identify the name of the method used below for the separation.

raketka [301]

Answer:

(a) Chromatography

(b) DNA fingerprinting

(c) Origin

(d) Sweet C consists of more colours than sweet D.

ii. The speed of colours in sweet C are proportional to one another, while that of colours in D is not.

Explanation:

Chromatography is one of the physical method of separating mixtures. This process composed of the ability of the constituents in a mixture to separate by virtue of rate of movement through a medium, thus separates into constituents.

It can be used to determine the soluble constituents of a given mixture. And for purification purpose.

3 0

3 years ago