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 
Melting temperature of Solid 
Temperature of liquid 
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 
at 159 K
= 159 K - 138 K = 21 K
Heat required to melt and raise the temperature of upto 223 K
= 223 K - 159 K = 64 K
Total heat to convert solid ethanol to liquid ethanol at given temperature :
(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.
Answer:
Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.
<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
<u>Chemistry</u>
<u>Atomic Structure</u>
<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:
- [DA] Multiply/Divide [Cancel out units]:
The following reaction gives a product with the molecular formula C₄H₈O₂. The diagram of the structure of the product can be seen in the image attached below.
The reaction between C₂H₂(ONa)₂ and C₂H₄Br results in the formation of the product C₄H₈O₂ and 2NaBr.
This reaction undergoes an SN₂ mechanism since there is no stable carbocation formed. In the reaction -O⁻Na⁺ attacks the ortho position in C₂H₄Br to form C₄H₈O₂.
In SN₂ mechanism is a nucleophilic substitution reaction where one bond is formed while another one is broken simultaneously.
The mechanism for the reaction can be seen in the image attached below.
Learn more about nucleophilic substitution reaction here:
brainly.com/question/4699407?referrer=searchResults
Answer:
Explanation:
The correct measurement is .710 s which is equal to .71 s so second measurement that is 0.71 s is most accurate measurement .
B. 0.71s is the most accurate .
Precision depends upon measuring instrument . Measurement by highly precise instrument has greater precision .
The measurement of 0.75 ± 0.002s must have been taken from high precise instrument because it is capable of making measurement upto 3 decimal points .
Hence
C 0.75 ± 0.002s is most precise measurement .
