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2 years ago

What are unit conversions used for?

Chemistry

1 answer:

lbvjy [14]2 years ago

6 0

Answer:

B: Unit conversions express an amount in a different unit.

Explanation:

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Explain how a bond forms between sodium and chlorine in sodium chloride (NaCl).

alexandr1967 [171]

Sodium has 1 valence electron and chlorine has 7 valence electrons and the goal is to get t 8 valence electrons then they attract together, forming table salt.

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3 years ago

how can you find the Frequency if you only have the wavelength? can you solve this example what is the Frequency of the waveleng

DiKsa [7]

Answer:

75000 Hz

Explanation:

f = V / λ (f= frequency, v=velocity of wave, lambda= wavelength)

alternatively, f = c / λ (f= frequency, c= speed of light- 3.00x10^8 m/s, lambda= wavelength)

f= [3.00x10^8 m/s]/[4000 m]

=75000 Hz

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2 years ago

How do chemists use systems and order in their work?

san4es73 [151]

Answer:

5 point) Chemists used systems and order because they study the basic unit of all forms of matter, which is the atom . However, there are several different kinds of atoms, called elements . Chemists organize these elements using the periodic table .

Explanation:

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2 years ago

Properties of matter with three example each

Cerrena [4.2K]

Answer:

Extensive properties vary with the amount of the substance and include mass, weight, and volume. Intensive properties, in contrast, do not depend on the amount of the substance; they include color, melting point, boiling point, electrical conductivity, and physical state at a given temperature.

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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