All categories

3 years ago

Determine the empirical formula for a compound that is found to contain

Chemistry

1 answer:

Sphinxa [80]3 years ago

7 0

Answer:

The empirical formula is PCl3

Explanation:

Mass of P is 30.97 g, thus 1.523 g of P equivalent to 0.05 moles of P

Mass of Cl is 35.45 g, thus 5.228 g of Cl equivalent to 0.15 moles of Cl

Therefore moles of P : moles of Cl = 0.05:0.15 = 1:3

Therefore the empirical formula, PCl3

You might be interested in

Which rock type(s) could be transformed into sediment?

iVinArrow [24]

Answer:

Explanation:

4 0

3 years ago

Read 2 more answers

Titanium has an HCP crystal structure, a c/a ratio of 1.669, an atomic weight of 47.87 g/mol, and a density of 4.51 g/cm3. Compu

IrinaK [193]

Answer : The atomic radius for Ti is, $1.45\times 10^{-8}cm$

Explanation :

Atomic weight = 47.87 g/mole

Avogadro's number $(N_{A})=6.022\times 10^{23} mol^{-1}$

First we have to calculate the volume of HCP crystal structure.

Formula used :

$\rho=\frac{Z\times M}{N_{A}\times V}$ .............(1)

where,

$\rho$ = density = $4.51g/cm^3$

Z = number of atom in unit cell (for HCP = 6)

M = atomic mass = 47.87 g/mole

$(N_{A})$ = Avogadro's number

V = volume of HCP crystal structure = ?

Now put all the values in above formula (1), we get

$4.51g/cm^3=\frac{6\times (47.87g/mol)}{(6.022\times 10^{23}mol^{-1}) \times V}$

$V=1.06\times 10^{-22}cm^3$

Now we have to calculate the atomic radius for Ti.

Formula used :

$V=6R^2c\sqrt{3}$

Given:

c/a ratio = 1.669 that means, c = 1.669 a

Now put (c = 1.669 a) and (a = 2R) in this formula, we get:

$V=6R^2\times (1.669a)\sqrt{3}$

$V=6R^2\times (1.669\times 2R)\sqrt{3}$

$V=(1.669)\times (12\sqrt{3})R^3$

Now put all the given values in this formula, we get:

$1.06\times 10^{-22}cm^3=(1.669)\times (12\sqrt{3})R^3$

$R=1.45\times 10^{-8}cm$

Therefore, the atomic radius for Ti is, $1.45\times 10^{-8}cm$

3 0

3 years ago

When ammonium phosphate and nickel(ii) nitrate solutions are mixed, what precipitates out?

Sphinxa [80]

2(NH4)3PO4 (aq) + 3Ni(NO3)2(aq) ------> Ni3(PO4)2(s) + 6NH4NO3 (aq)

Ni3(PO4)2 is a precipitate.

5 0

4 years ago

Read 2 more answers

A 35.6 g sample of ethanol (C2H5OH) is burned in a bomb calorimeter, according to the following reaction. If the temperature ros

PilotLPTM [1.2K]

<h3>Answer:</h3>

1.24 × 10³ kJ/mol

<h3>Explanation:</h3>

From the question we are given;

Heat capacity of the calorimeter =23.3 kJ/°C

Temperature change, ΔT = 76°C - 35°C

= 41 °C

Mass of ethanol = 35.6 g

Molar mass of ethanol = 46.07 g/mol

We are required to determine the molar enthalpy

We can use the following steps:

<h3> Step 1 : Calculate the heat change of the reaction</h3>

Heat change will be equivalent to heat gained by the calorimeter.

Therefore;

Heat = heat capacity × change in temperature

Q = CΔT

= 23.33 kJ/°C × 41°C

= 955.3 kJ

<h3>Step 2 : Calculate the moles of ethanol burned </h3>

Moles = mass ÷ Molar mass

Therefore;

Moles of ethanol = 35.6 g ÷ 46.07 g/mol

= 0.773 moles

<h3>Step 3: Calculate the molar enthalpy of the reaction </h3>

Heat change for 0.773 moles of ethanol is 955.3 kJ

0.773 moles = 955.3 kJ

1 mole will have ,

= 955.3 kJ ÷ 0.773 moles

= 1235.83 kJ/mol

= 1.24 × 10³ kJ/mol

But since the reaction is exothermic (release of heat) then the enthalpy change will have a negative sign.

Thus;

ΔH = -1.24 × 10³ kJ/mol

7 0

4 years ago

Calculate the pH of a solution formed by dissolving 0.040 moles of solid sodium lactate, NaC3H5O3, in 50.0 mL of 1.0 M HC3H5O3.

natima [27]

The pH of the solution is 3,76

Why?

To solve this problem we have to apply the Henderson-Hasselbach equation, which is used whenever we need to calculate the pH of a solution of an acid HA (Lactic Acid) and its conjugate base A⁻ (Sodium Lactate)

We can use either moles or concentrations for this equation. In this case, we are going to use the moles, and we are going to take the pKa of lactic acid as 3,86:

$pH=pKa+log(\frac{nA^- }{nHA} )=3,86+log(\frac{(0,04moles)}{(0,05mL)*(1.0M)} )\\\\pH=3,76$

Have a nice day!

#LearnwithBrainly

3 0

4 years ago