Is it general principal that more abundant isotopes exist in

Calculate a reasonable amount (mass in g) of your unknown acid to use for a titration. You will want about 30 mL of titrant to g

Vinil7 [7]

Answer:

"0.60 g" is the appropriate solution.

Explanation:

The given values are:

Volume of base,

= 30 ml

Molarity of base,

= 0.05 m

Molar mass of acid,

= 400 g/mol

As we know,

⇒ $Molarity=\frac{Number \ of \ moles \ of \ base}{Number \ of \ solution}$

On substituting the values, we get

⇒ $0.05=\frac{Number \ of \ moles \ of \ base}{30\times 10^{-3}}$

⇒ $Number \ of \ moles \ of \ base=0.05\times 30\times 10^{-3}$

⇒ $=1.5\times 10^{-3}$

hence,

⇒ $Moles \ of \ acid=\frac{Mass \ of \ acid}{Molar \ mass \ of \ acid}$

On substituting the values, we get

⇒ $1.5\times 10^{-3}=\frac{Mass \ of \ acid}{400}$

⇒ $Mass \ of \ acid=1.5\times 10^{-3}\times 400$

⇒ $=0.60 \ g$

8 0

2 years ago

All reactions involving a change in temperature are exothermic. a. True b. False

diamong [38]

False. An increase in temperature is an exothermic reaction. However, when a temperature decreases this is known as an endothermic reactionz

8 0

3 years ago

Which one of the following is a correct representation of an alpha particle?

Alex Ar [27]

Answer:

₂He⁴

Explanation:

Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.

Properties of alpha radiation:

Alpha radiations can travel in a short distance.

These radiations can not penetrate into the skin or clothes.

These radiations can be harmful for the human if these are inhaled.

These radiations can be stopped by a piece of paper.

₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy

6 0

3 years ago

Calculate the standard enthalpy change for the reaction at 25 ∘ 25 ∘ C. Standard enthalpy of formation values can be found in th

WINSTONCH [101]

Answer: The standard enthalpy change of the reaction is coming out to be -16.3 kJ

Explanation:

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as $\Delta H$

The equation used to calculate enthalpy change is of a reaction is:

$\Delta H_{rxn}=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)]$

For the given chemical reaction:

$Mg(OH)_2(s)+2HCl(g)\rightarrow MgCl_2(s)+2H_2O(g)$

The equation for the enthalpy change of the above reaction is:

$\Delta H_{rxn}=[(1\times \Delta H_f_{(MgCl_2(s))})+(2\times \Delta H_f_{(H_2O(g))})]-[(1\times \Delta H_f_{(Mg(OH)_2(s))})+(2\times \Delta H_f_{(HCl(g))})]$

We are given:

$\Delta H_f_{(Mg(OH)_2(s))}=-924.5kJ/mol\\\Delta H_f_{(HCl(g))}=-92.30kJ/mol\\\Delta H_f_{(MgCl_2(s))}=-641.8kJ/mol\\\Delta H_f_{(H_2O(g))}=-241.8kJ/mol$

Putting values in above equation, we get:

$\Delta H_{rxn}=[(1\times (-641.8))+(2\times (-241.8))]-[(1\times (-924.5))+(2\times (-92.30))]\\\\\Delta H_{rxn}=-16.3kJ$

Hence, the standard enthalpy change of the reaction is coming out to be -16.3 kJ

6 0

3 years ago

Explain, in terms of electron configuration why atoms of the radioisotope produced by the sixth decay in the U-238 disintegratio

Troyanec [42]

Answer:

The reason they don't react is because Elements with full octets are stable, the Elements with no unpaired electrons do not react at all in the decay.

4 0

2 years ago