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What devices will you use to measure the mass and the volume in this experiment? (density)

bekas [8.4K]

Answer:

Methods for determining or delivering precise volumes include volumetric pipets and pycnometers; less precise methods include burets, graduated cylinders, and graduated pipets. In this experiment, you will measure masses and volumes to determine density. Four different metal cylinders are investigated.

Explanation:

8 0

2 years ago

What is the molecular formula of a compound that has a molecular mass of 54 and the empirical formula is C2H3

iren [92.7K]

To find the molecular formula from the empirical formula, you need to find a multiple (x) that will give you the molar mass of the compound which in the question is 54 g/mol.

If C₂H₃ is the empirical formula
molar mass of empirical formula = (12 × 2) + (1 × 3) g/mol
= 27 g/mol
let x = multiple
let molecular formula = C₂ₓ H₃ₓ

multiple = molecular mass ÷ empirical mass
= 54 g/mol ÷ 27 g/mol
= 2

If molecular formula = C₂ₓ H₃ₓ

then molecular formula = C₂₍₂₎H₃₍₂₎

= C₄H₆

8 0

3 years ago

Substance ΔG°f(kJ/mol) M3O4(s) −8.80 M(s) 0 O2(g) 0 Consider the decomposition of a metal oxide to its elements, where M represe

baherus [9]

Answer:

The equilibrium constant is $K =0.02867$

The equilibrium pressure for oxygen gas is $P_{O_2} = 0.09367\ atm$

Explanation:

From the question we are told that

The equation of the chemical reaction is

$M_2 O_3 _{(s)} ----> 2M_{(s)} + \frac{3}{2} O_2_{(g)}$

The Gibbs free energy for $M_3 O_4_{(s)}$ is $\Delta G^o_{1} = -8.80 \ kJ/mol$

The Gibbs free energy for $M{(s)}$ is $\Delta G^o_{2} = 0 \ kJ/mol$

The Gibbs free energy for $O_2{(s)}$ is $\Delta G^o_{3} = 0 \ kJ/mol$

The Gibbs free energy of the reaction is mathematically represented as

$\Delta G^o_{re} = \sum \Delta G^o _p - \sum G^o _r$

$\Delta G^o_{re} = \sum \Delta G^o _1 - \sum( G^o _2 +G^o _3)$

Substituting values

From the balanced equation

$\Delta G^o_{re} =[ (2 * 0) + (\frac{3}{2} * 0 )] - [1 * - 8.80]$

$\Delta G^o_{re} = 8.80 kJ/mol =8800J/mol$

The Gibbs free energy of the reaction can also be represented mathematically as

$\Delta G^o_{re} = -RTln K$

Where R is the gas constant with a value of $R = 8.314 J/mol \cdot K$

T is the temperature with a given value of $T = 298 K$

K is the equilibrium constant

Now equilibrium constant for a reaction that contain gas is usually expressed in term of the partial pressure of the reactant and products that a gaseous in state

The equilibrium constant for this chemical reaction is mathematically represented as

$K_p =[ P_{O_2}]^{\frac{3}{2} }$

Where $[ P_{O_2}]$ is the equilibrium pressure of oxygen

The p subscript shows that we are obtaining the equilibrium constant using the partial pressure of gas in the reaction

Now equilibrium constant the subject on the second equation of the Gibbs free energy of the reaction

$K = e^{- \frac{\Delta G^o_{re}}{RT} }$

Substituting values

$K= e^{\frac{8800}{8.314 * 298} }$

$K =0.02867$

Now substituting this into the equation above to obtain the equilibrium of oxygen

$0.02867 = [P_{O_2}]^{[\frac{3}{2} ]}$

multiplying through by $1 ^{\frac{2}{3} }$

$P_{O_2} = [0.02867]^{\frac{2}{3} }$

$P_{O_2} = 0.09367\ atm$

3 0

3 years ago

How many moles of aluminum are needed to react completely with 1.2 mol of feo

Lelu [443]

Answer:

0.80 mol Al

Explanation:

1) Word reaction:

Aluminum + ferrous oxide → aluminum oxide + iron

This is a single replacement reaction, in which aluminum, a more acitve metal than iron, replaces the iron in the ferrous oxide to form aluminum oxide and iron.

2) Skeleton chemical equation:

Al + FeO → Al₂O₃ + Fe

3) Balanced chemical equation:

Add the coeffcients to comply with the law of conservation of mass:

2Al + 3FeO → Al₂O₃ + 3Fe

4) Mole ratio of Al and FeO:

2 mol Al : 3 mol FeO

5) Set a proportion with the unkown and solve:

x / 1.2 mol FeO = 2 mol Al / 3 mol FeO

x = 1.2 mol FeO × 2 mol Al / 3 mol FeO = 0.80 mol Al ← answer

3 0

3 years ago

What amount in moles does 242 L of carbon dioxide occupy at 1.32 atm and 20 degrees C

Gelneren [198K]

Answer:

13.28 mol.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = 1.32 atm).

V is the volume of the gas in L (V = 242.0 L).

n is the no. of moles of the gas in mol (n = ??? mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K).

T is the temperature of the gas in K (T = 20.0° + 273 = 293.0 K).

∴ n = PV/RT = (1.32 atm)(242.0 L)/(0.0821 L.atm/mol.K)(293.0 K) = 13.28 mol.

7 0

3 years ago

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