Is tarnishing silver physical or chemical

Why is it impossible to have an undiscovered element that would fit between sodium and magnesuim

Stolb23 [73]

Answer:

Sodium has 11 protons and Magnesium has 12. The way that the periodic table is set up doesn't allow for any elements to be in between. The element would have to have 11.5 protons, which is impossible

4 0

3 years ago

A weather balloon is filled with helium that occupies a volume of 3.93 104 L at 0.995 atm and 32.0°C. After it is released, it r

user100 [1]

Answer: Thus the volume of the balloon at that new location is $4.65\times 10^4L$

Explanation:

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 0.995 atm

$P_2$ = final pressure of gas = 0.720 atm

$V_1$ = initial volume of gas = $3.93\times 10^4L$

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $32.0^oC=273+32.0=305.0K$

$T_2$ = final temperature of gas = $-11.7^oC=273-11.7=261.3K$

Now put all the given values in the above equation, we get:

$\frac{0.995\times 3.93\times 10^4}{305.0}=\frac{0.720\times V_2}{261.3}$

$V_2=4.65\times 10^4L$

Thus the volume of the balloon at that new location is $4.65\times 10^4L$

4 0

3 years ago

A 1.8 g sample of octane C8H18 was burned in a bomb calorimeter and the temperature of 100 g of water increased from 21.36 C to

melomori [17]

Answer:

HEAT OF COMBUSTION PER GRAM OF OCTANE IS 1723.08 J OR 1.72 KJ/G OF HEAT

HEAT OFF COMBUSTION PER MOLE OF OCTANE IS 196.4 KJ/ MOL OF HEAT

Explanation:

Mass of water = 100 g

Change in temperature = 28.78 °C - 21.36°C = 7.42 °C

Heat capcacity of water = 4.18 J/g°C

Mass of octane = 1.8 g

Molar mass of octane = C8H18 = (12 * 8 + 1 * 18) g/mol= 96 + 18 = 114 g/mol

First is to calculate the heat evolved when 100 g of water is used:

Heat = mass * specific heat capacity * change in temperature

Heat = 100 * 4.18 * 7.42

Heat = 3101.56 J

In other words, 3101.56 J of heat was evolved from the reaction of 1.8 g octane with water.

Heat of combustion of octane per gram:

1.8 g of octane produces 3101.56 J of heat

1 g of octane will produce ( 3101.56 * 1 / 1.8)

= 1723.08 J of heat

So, heat of combustion of octane per gram is 1723.08 J

Heat of combustion per mole:

1.8 g of octane produces 3101.56 J of heat

1 mole of octane will produce X J of heat

1 mole of octane = 114 g/ mol of octane

So we have:

1.8 g of octane = 3101.56 J

114 g of octane = (3101.56 * 114 / 1.8) J of heat

= 196 432.13 J

= 196. 4 kJ of heat

The heat of combustion of octane per mole is 196.4 kJ /mol.

Mass of water = 100 g

Change in temperature = 28.78 °C - 21.36°C = 7.42 °C

Heat capcacity of water = 4.18 J/g°C

Mass of octane = 1.8 g

Molar mass of octane = C8H18 = (12 * 8 + 1 * 18) g/mol= 96 + 18 = 114 g/mol

First is to calculate the heat evolved when 100 g of water is used:

Heat = mass * specific heat capacity * change in temperature

Heat = 100 * 4.18 * 7.42

Heat = 3101.56 J

8 0

3 years ago

PLEASE HELP ME!! List the equipment you need for electrolysis.

natka813 [3]

Sodium, chlorine, magnisium and alumium

Idk if that helps or not

6 0

4 years ago

Erioglucine is a blue-colored dye that absorbs its complementary color, red, in aqueous solution around 645 nm. Unfortunately, t

ExtremeBDS [4]

Answer:

For the control experiment: $0.0552 M$ of aqueous solution of erioglaucine has absorbance of $0.035 M\\$

From Lambert-Beer's law we know:

$Absorbance = e\cdot c \cdot l\\$

Here; e is the molar absorptivity coefficient of erioglaucine

l = length of cuvette in which the solution is taken = $1 cm$

A sorbance by the erioglaucine = total absorbance - absorbance by distilled $water = 0.331-0.019 = 0.312$

So; by putting the values in the above equation; we get:

$0.312 = 0.0552 M \cdot e\cdot~1cm\\$

So; $e = \frac{0.331}{0.0552} M^{-1}cm^{-1}= 5.65 M^{-1}cm^{-1}$

The molar absorptivity coefficient of erioglaucine is $5.65 M^{-1}cm^{-1}\\$

The absorbance of erioglaucine in distilled water (contaminated with metal ions) is: $0 .217$

The absorbance of distilled water is $0.019$

So; absorbance of erioglaucine itself is : $0.217-0.019 = 0.198$

Again using Lambert Beer law; we get:

$A= e\cdot c\cdot l$

$0.198 = 5.65 M^{-1}cm^{-1} \cdot c \cdot 1 cm$ $( c = concentrartion)$

c = 0.198/5.65 M = 0.035 M

The concentration of the erioglaucine is $0.035 M\\$

Explanation:

4 0

4 years ago