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2 years ago

What are the compounds empirical and molecular formulas

Chemistry

1 answer:

Liono4ka [1.6K]2 years ago

5 0

Answer:

The empirical formula is the simplest ratio of atoms while molecular is the actual formula.

Explanation:

Empirical Formula is the simplest ratio of atoms present in the compound.

The molecular formula shows the actual number of atoms present in the compound.

For example, CH is the empirical formula and C6H6 is the molecular formula of benzene.

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Balance the Following Equations: SiCl4 + H2O = SiO2 + HCl

dimaraw [331]

The answer would be D.

SiCl4 + 2H2O → SiO2 + 4HCl (balanced equation)

5 0

3 years ago

consider an exceptionally weak acid, HA, with Ka= 1 x 10-20. you make 0.1M solution of the salt NA. what is the pH.

iogann1982 [59]

Answer:

$pH=10.5$

Explanation:

Hello,

In this case, the dissociation of the given weak acid is:

$HA\rightleftharpoons H^++A^-$

Therefore, the law of mass action for it turns out:

$Ka=\frac{[H^+][A^-]}{[HA]}$

That in terms of the change $x$ due to the reaction extent is:

$1x10^{-23}=\frac{x*x}{0.1-x}$

Thus, by solving with the quadratic equation or solver, we obtain:

$x=31.6x10^{-12}M$

Which clearly matches with the hydrogen concentration in the solution, therefore, the pH is:

$pH=-log(-31.6x10^{-12})\\pH=10.5$

Regards.

5 0

3 years ago

A scientist measures the standard enthalpy change for the following reaction to be 67.9 kJ:

bekas [8.4K]

Answer: The standard enthalpy of formation of $H_2O(g)$ is -252.1 kJ/mol.

Explanation:

The balanced chemical reaction is,

$Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)$

The expression for enthalpy change is,

$\Delta H=[n\times H_f_{products}]-[n\times H_f_{reactantss}]$

Putting the values we get :

$\Delta H=[2\times H_f{Fe}+3\times H_f{H_2O}]-[1\times H_f{Fe_2O_3}+3\times H_f{H_2}]$

$67.9kJ=[(2\times 0)+(3\times H_f{H_2O})]-[(1\times -824.2kJ/mol)+3\times 0kJ/mol)]$

$H_f{H_2O}=-252.1kJ/mol$

Thus standard enthalpy of formation of $H_2O(g)$ is -252.1 kJ/mol.

3 0

3 years ago

A sailor on a trans-Pacific solo voyage notices one day that if he puts 735.mL of fresh water into a plastic cup weighing 25.0g,

Gennadij [26K]

Answer:

Amount of salt in 1 L seawater = 34 g

Explanation:

According to Archimedes' principle, mass of freshwater and cup = mass of equal volume of seawater

mass of freshwater = density * volume

1 cm³ = 1 mL

mass of freshwater = 0.999 g/cm³ * 735 cm³ = 734.265 g

mass of freshwater + cup = 734.265 + 25 = 759.265 g

Therefore, mass of equal volume of seawater = 759.265 g

Volume of seawater displaced = 735 mL = 0.735 L (assuming the cup volume is negligible)

1 liter = 1000 cm³ = 1000 mL;

Density of seawater = mass / volume

Density of seawater = 759.265 g / 0.735 L = 1033.01 g/L

Density of freshwater in g/L = 0.999 g/ (1/1000) L = 999 g/L

mass of 1 Liter seawater = 1033.01 g

mass of 1 Liter freshwater = 999 g

mass of salt dissolved in 1 L of seawater = 1033.01 g - 999 g = 34.01 g

Therefore, amount of salt in 1 L seawater = 34 g

4 0

3 years ago

What are two ways in which you can increase the potential energy of a marble on ramp

zlopas [31]

Answer:

You can make the ramp really steep and hold the marble at the top of it

Explanation:

6 0

3 years ago