What is the molarity of a solution in which 0.257 moles of HNO2 is dissolved in 490ml of water?

What is the differentences between atomic number and atomic mass?

natima [27]

Atomic number is number on periodic table, mass is how big element is

3 0

2 years ago

Which statements are consistent with Dalton"s atomic theory as it was originally stated? Why? a. Sulfur and oxygen atoms have th

Vlad [161]

The question is incomplete, the complete question is:

Which statements are consistent with Dalton's atomic theory as it was originally stated? Why?

a. Sulfur and oxygen atoms have the same mass.

b. All cobalt atoms are identical.

c. Potassium and chlorine atoms combine in a 1:1 ratio to form potassium chloride.

d. Lead atoms can be converted into gold.

Answer: The correct options are b) and c).

Explanation:

Some of the postulates of Dalton's atomic theory are:

All matter is made of very tiny particles called atoms that participate in chemical reactions
Atoms are indivisible particles that cannot be created or destroyed in a chemical reaction
Atoms of a given element are identical in mass and chemical properties
Atoms of different elements have different masses and chemical properties.
Atoms combine in the ratio of small whole numbers to form compounds.
The relative number and kinds of atoms are constant in a given compound.

For the given options:

For a:

The statement is inconsistent with the theory as no two elements can have the same mass. Only atoms of the same element can have the same mass.

For b:

This is consistent with the theory as atoms of the same element are identical.

For c:

This is consistent with the theory as atoms combine in a simple whole number ratio.

For d:

The statement is inconsistent with the theory as atoms of one element cannot be changed to atoms of other element.

Hence, the correct options are b) and c).

5 0

2 years ago

fish give off the compound ammonia which has a PH above 7. To which class of compounds does ammonia belong?

fiasKO [112]

The class of compounds that ammonia belongs to is it is categorized as a basic compound. As it posses a pH value or rating above 7, which is characteristic of basic substances, solutions.

5 0

3 years ago

Read 2 more answers

What is one substance that is 100x more acidic than baking soda

daser333 [38]

Answer:

An acid is a substance that donates hydrogen ions. Because of this, when an acid is dissolved in water, the balance between hydrogen ions and hydroxide ions is shifted. Now there are more hydrogen ions than hydroxide ions in the solution. This kind of solution is acidic.

Explanation:

8 0

2 years ago

What is the total energy change for the following reaction:CO+H2O-CO2+H2

Alekssandra [29.7K]

Answer:

$\large \boxed{\text{-41.2 kJ/mol}}$

Explanation:

Balanced equation: CO(g) + H₂O(g) ⟶ CO₂(g) + H₂(g)

We can calculate the enthalpy change of a reaction by using the enthalpies of formation of reactants and products

$\Delta_{\text{rxn}}H^{\circ} = \sum \left( \Delta_{\text{f}} H^{\circ} \text{products}\right) - \sum \left (\Delta_{\text{f}}H^{\circ} \text{reactants} \right)$

(a) Enthalpies of formation of reactants and products

$\begin{array}{cc}\textbf{Substance} & \textbf{$\Delta_{\text{f}}$H/(kJ/mol}) \\\text{CO(g)} & -110.5 \\\text{H$_{2}$O} & -241.8\\\text{CO$_{2}$(g)} & -393.5 \\\text{H$_{2}$(g)} & 0 \\\end{array}$

(b) Total enthalpies of reactants and products

$\begin{array}{ccr}\textbf{Substance} & \textbf{Contribution)/(kJ/mol})&\textbf{Sum} \\\text{CO(g)} & -110.5& -110.5 \\\text{H$_{2}$O(g)} &-241.8& -241.8\\\textbf{Total}&\textbf{for reactants} &\mathbf{ -352.3}\\&&\\\text{CO}_{2}(g) & -393.5&-393.5 \\\text{H}_{2} & 0 & 0\\\textbf{Total}&\textbf{for products} & \mathbf{-393.5}\end{array}$

(c) Enthalpy of reaction $\Delta_{\text{rxn}}H^{\circ} = \sum \left( \Delta_{\text{f}} H^{\circ} \text{products}\right) - \sum \left (\Delta_{\text{f}}H^{\circ} \text{reactants} \right)= \text{-393.5 kJ/mol - (-352.3 kJ/mol}\\= \text{-393.5 kJ/mol + 352.3 kJ/mol} = \textbf{-41.2 kJ/mol}\\ \text{The total enthalpy change is $\large \boxed{\textbf{-41.2 kJ/mol}}$}$

4 0

2 years ago