Will give brainliest for correct answer and quick answer! help ;w;

Ethanol (c2h5oh) melts at -114Â°c. the enthalpy of fusion is 5.02 kj/mol. the specific heats of solid and liquid ethanol are 0.9

Nimfa-mama [501]

Answer: 4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.

Explanation:

Temperature of Solid $C_2H_5OH=-135^oC=138 K(0^oC=273K)$

Melting temperature of Solid $C_2H_5OH=114^oC=159 K$

Temperature of liquid $C_2H_5OH=-50^oC=223K$

Specific heats of solid ethanol = 0.97 J/gK

Specific heats of liquid ethanol = 2.3 J/gK

Heat required to melt the the 25 g solid $C_2H_5OH$ at 159 K

$\Delta T_1$ = 159 K - 138 K = 21 K

$Q_1=mc\Delta T= 25\times 0.97J/gK\times 21 K=509.25 J$

Heat required to melt and raise the temperature of $C_2H_5OH$ upto 223 K

$\Delta T_2$ = 223 K - 159 K = 64 K

$Q_2=mc\Delta T= 25\times 2.3J/gK\times 64 K=3680 J$

Total heat to convert solid ethanol to liquid ethanol at given temperature :

$Q_1+Q_2=509.25 J+3680 J=4189.25 J=4.18925 kJ$ (1kJ=1000J)

Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.

6 0

3 years ago

Which of the following shows a decrease in entropy?

shusha [124]

Precipitation hope this helped you

4 0

3 years ago

Which cell structure is found in animals, but not in plants?

andrezito [222]

Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.

4 0

3 years ago

Read 2 more answers

Fe(s) + O2 (g) → Fe3+ O2− What most likely happens during this reaction?

Musya8 [376]

Answer : The most likely happens during this reaction is, Oxidation-reduction

Explanation :

The balanced reaction will be,

$4Fe(s)+3O_2(g)\rightarrow 2Fe_2O_3(s)$

In this reaction, neutral iron loses 3 electrons and oxidizes in (+3) state, $Fe^{3+}$ and neutral oxygen gains 2 electrons and reduces in (-2) state, $O^{2-}$

When iron react with oxygen gas to give iron oxide. This process is known as iron rusting. During the reaction, oxidation-reduction process occurs.

Oxidation : It is a type of chemical reaction in which a substance loses its electrons. Or we can say that in oxidation, the oxidation number increases.

Reduction : It is a type of chemical reaction in which a substance gains its electrons. Or we can say that in reduction, the oxidation number decreases.

5 0

3 years ago

Given the following unbalanced equation:

Lorico [155]

<h3>Answer:</h3>

8.01 mol MgO

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Moles
Compounds

<u>Stoichiometry</u>

Using Dimensional Analysis
Analyzing Reactions RxN

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Unbalanced] Mg + O₂ → MgO

[RxN - Balanced] 2Mg + O₂ → 2MgO

[Given] 8.01 moles Mg

[Solve] moles MgO

<u>Step 2: Identify Conversions</u>

[RxN] 2 mol Mg → 2 mol MgO

<u>Step 3: Stoich</u>

[DA] Set up: $\displaystyle 8.01 \ mol \ Mg(\frac{2 \ mol \ MgO}{2 \ mol \ Mg})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 8.01 \ mol \ MgO$

3 0

3 years ago