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3 years ago

9

The reaction in Fe + O2→Fe2O3 is an example of a(n): A. combination reaction. B. decomposition reaction. C. aqueous reaction. D.

single-replacement reaction

1 answer:

motikmotik3 years ago

8 0

This is a combination reaction because two molecules becomes one

A + B ---> AB

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A solution is prepared by mixing 0.3355 moles of NaNO3 (84.995 g mol-1) with 235.0 g of water (18.015 g mol-1). Its density is 1

larisa86 [58]

Answer:

Molality = 1.428m

Explanation:

Molality, m, is an unit of concentration defined as the ratio between moles of solute and kg of solvent:

Molality: Moles solute / kg solvent.

In the problem, water is the solvent (Is the compound in the higher quantity) whereas NaNO₃ is the solute.

Moles of solute: 0.3355moles NaNO₃.

Kg solvent:

$235.0g\frac{1kg}{1000g} = 0.2350kg$

Thus, molality of the solution is:

Molality = 0.3355 moles NaNO₃ / 0.2350kg

<h3>Molality = 1.428m</h3>

6 0

3 years ago

A scientist measures the standard enthalpy change for the following reaction to be 81.1 kJ :2CO2(g) + 5 H2(g)C2H2(g) + 4 H2O(g)B

posledela

<u>Answer:</u> The enthalpy of the formation of $CO_2(g)$ is coming out to be -410.8 kJ/mol.Z

<u>Explanation:</u>

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 $\Delta H^o$

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

$\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f(product)]-\sum [n\times \Delta H^o_f(reactant)]$

For the given chemical reaction:

$2CO_2(g)+5H_2(g)\rightarrow C_2H_2(g)+4H_2O(g)$

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

$\Delta H^o_{rxn}=[(1\times \Delta H^o_f_{(C_2H_2(g))})+(4\times \Delta H^o_f_{(H_2O(g))})]-[(2\times \Delta H^o_f_{(CO_2(g))})+(5\times \Delta H^o_f_{(H_2(g))})]$

We are given:

$\Delta H^o_f_{(H_2O(g))}=-241.8kJ/mol\\\Delta H^o_f_{(H_2(g))}=0kJ/mol\\\Delta H^o_f_{(C_2H_2(g))}=226.7kJ/mol\\\Delta H^o_{rxn}=81.1kJ$

Putting values in above equation, we get:

$81.1=[(1\times (226.7)})+(4\times (-241.8))]-[(2\times \Delta H^o_f_{(CO_2(g))})+(5\times (0))]\\\\\Delta H^o_f_{(CO_2(g))}=-410.8kJ/mol$

Hence, the enthalpy of the formation of $CO_2(g)$ is coming out to be -410.8 kJ/mol.

8 0

3 years ago

The only type of movement particles in a solid do is

Nina [5.8K]

Answer

:small vibrational movements.

Explanation:

The particles of a solid are not able to move out of their positions relative to one another, but do have small vibrational movements.

___________________________________________________________

-Darkspirit-

6 0

3 years ago

You will mostly find me in solid form at room temperature.

AlexFokin [52]

Nonmetal is the correct answer

5 0

3 years ago

Express the sum of 1111 km and 222 km using the correct number of significant digits

kenny6666 [7]

1333 KM is the sum,

6 0

4 years ago

Read 2 more answers