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3 years ago

How is the mass of 1 mole of an element determined

1 answer:

3 0

One mole (abbreviated mol) is equal to 6.022×1023 molecular entities (Avogadro's number), and each element has a different molar mass depending on the weight of 6.022×1023 of its atoms (1 mole). The molar mass of any element can be determined by finding the atomic mass of the element on the periodic table.

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A gas has a volume of 10 liters under a pressure of 745 mm of Hg.

aksik [14]

Answer:

Volume is 10.35 L

Explanation:

we are given;

Initial volume v₁ is 10 L
Initial pressure, P₁ as 745 mmHg
New pressure ,P₂ as 720 mmHg

We are required to determine the new volume, V₂

We are going to use the Boyle's law;

According to Boyle's law the volume and the pressure of a fixed mass of a gas are inversely proportional at a constant temperature.

Therefore;

P₁α 1/V

That is;

P = k/V

k = PV

At different conditions;

P₁V₁ = P₂V₂

Rearranging the formula;

V₂ = P₁V₁ ÷ P₂

Thus;

New volume = (10 L× 745 mmHg) ÷ 720 mmHg

= 10.35 L

Thus, the new volume of the gas at the new pressure is 10.35 L

8 0

3 years ago

A piece of hot metal is put into an equal mass of water. The water temperature rises 5o and the metal’s temperature drops 10o. W

Mice21 [21]

Answer:

The answer to your question is Cm = 2.093 J/kg°C

Explanation:

Data

mass metal = mass of water

Δ water = 5°

Δ metal = 10°

Cm = ?

Cw = 4.186 J/Kg°C

Formula

for metal for water

mCmΔTm = mCwΔTw

Cancel mass of metal

Cm ΔTm = CwΔTw

solve for Cm

Cm = (CwΔTw) / ΔTm

Substitution

Cm = (4.186 x 5) / 10

Simplification

Cm = 20.93 / 10

Result

Cm = 2.093 J/kg°C

5 0

3 years ago

The gradient of a stream depends on its

solong [7]

The gradient of a stream ( or commonly knwon as path of the stream) depend on its :
- Slope of the land,
- Geologic Structures , as in its fractures and faults
- rock hardess
- And its water retention

4 0

3 years ago

The standard reduction potentials for the Ag+|Ag(s) and Zn2+| Zn(s) half-cell reactions are +0.799 V and -0.762 V, respectively.

mihalych1998 [28]

Answer: The potential of the given cell is 1.551 V

Explanation:

The given chemical cell follows:

$Zn(s)|Zn^{2+}(0.125M)||Ag^{+}(0.240M)|Ag(s)$

Oxidation half reaction: $Zn(s)\rightarrow Zn^{2+}(0.125M)+2e^-;E^o_{Zn^{2+}/Zn}=-0.762V$

Reduction half reaction: $Ag^{+}(0.240M)+e^-\rightarrow Ag(s);E^o_{Ag^{+}/Ag}=0.799V$ ( × 2)

Net cell reaction: $Zn(s)+2Ag^{+}(0.240M)\rightarrow Zn^{2+}(0.125M)+2Ag(s)$

Oxidation reaction occurs at anode and reduction reaction occurs at cathode.

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

Putting values in above equation, we get:

$E^o_{cell}=0.799-(-0.762)=1.561V$

To calculate the EMF of the cell, we use the Nernst equation, which is:

$E_{cell}=E^o_{cell}-\frac{0.059}{n}\log \frac{[Zn^{2+}]}{[Ag^{+}]^2}$

where,

$E_{cell}$ = electrode potential of the cell = ? V

$E^o_{cell}$ = standard electrode potential of the cell = +1.561 V

n = number of electrons exchanged = 2

$[Zn^{2+}]=0.125M$

$[Ag^{+}]=0.240M$

Putting values in above equation, we get:

$E_{cell}=1.561-\frac{0.059}{2}\times \log(\frac{(0.125)}{(0.240)^2})$

$E_{cell}=1.551V$

Hence, the potential of the given cell is 1.551 V

6 0

4 years ago

A chemical equations that includes the amount of heat released or absorbed during a reaction

Tema [17]

The potential energy stored in the form of heat is called as enthalpy of a system. The reactions in which a system absorbs heat, are called as endothermic reactions. The ones in which a system releases heat, are called as exothermic reactions

3 0

3 years ago