Wat helps measure 26 ML of a liquid

Identify the chemical reactions as endothermic, exothermic, or neither. An egg cooking: A candle burning: Plaster and water comb

lianna [129]

Answer :

An egg cooking is an endothermic reaction.

A candle burning and Plaster & water combining and becoming warm are exothermic reaction.

Salt being added to water, with no change in temperature neither endothermic nor exothermic reaction.

Explanation :

Endothermic reaction : It is a type of reaction in which energy is absorbed in the form of heat from the surroundings.

Exothermic reaction : It is a type of reaction in which energy is released in the form of heat from the system.

An egg cooking : In this process, the energy is absorbed in the form of heat.

A candle burning and Plaster & water combining and becoming warm : In both the process, the energy is released in the form of heat.

Salt being added to water, with no change in temperature : In this process, neither energy released nor absorbed.

5 0

3 years ago

Read 2 more answers

1 lb of CO2 occupies 0.6 ft^3 at a pressure of 200 psi. Determine the temperature of the system.

Anarel [89]

Answer: The temperature of the system is 273 K

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of carbon dioxide = 1 lb = 453.6 g (Conversion factor: 1 lb = 453.6 g)

Molar mass of carbon dioxide = 44 g/mol

Putting values in above equation, we get:

$\text{Moles of carbon dioxide}=\frac{453.6g}{44g/mol}=10.31mol$

To calculate the temperature of gas, we use the equation given by ideal gas equation:

PV = nRT

where,

P = Pressure of carbon dioxide = 200 psia = 13.6 atm (Conversion factor: 1 psia = 0.068 atm)

V = Volume of carbon dioxide = $0.6ft^3=16.992L$ (Conversion factor: $1ft^3=28.32L$ )

n = number of moles of carbon dioxide = 10.31 mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the system = ?

Putting values in above equation, we get:

$13.6atm\times 16.992L=10.31mol\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times T\\\\T=273K$

Hence, the temperature of the system is 273 K

8 0

3 years ago

What is the average mass of an electron? A. 1 amu B. 1,837 amu C. 1/1,837

diamong [38]

Answer:

C. 1/1,837

Explanation:

3 0

4 years ago

In order to expand agriculture and urban areas to meet increased demand for growing populations, water supplies often have to be

VMariaS [17]

answer:

lets say we have a big lake with a lot of animals and you want to move the water to somewhere else. A lot of animals and fish, frogs will have to find a new home!

7 0

3 years ago

C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l), ΔH = –1.37 × 103 kJ For the combustion of ethyl alcohol as described in the above equati

babymother [125]

Answer:

The true statements are: I. The reaction is exothermic.

II. The enthalpy change would be different if gaseous water was produced.

Explanation:

The given chemical reaction: C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l), ΔH= -1.37×10³kJ

1. In an exothermic reaction, heat or energy is released from the system to the surrounding. Thus for an exothermic process the change in enthalpy is less than 0 or negative (ΔH < 0) .

Since the enthalpy change for a combustion reaction is negative. Therefore, the given reaction is exothermic.

2. The change in enthalpy (ΔH) of a reaction is equal to difference of the sum of standard enthalpy of formation (ΔHf°) of the products and the reactants.

ΔHr° = ∑ n.ΔHf°(products) − ∑ n.ΔHf°(reactants)

As the value of ΔHf° of water in gaseous state and liquid state is not the same.

Therefore, the enthalpy change of the reaction will be different, if gaseous water was present instead of liquid water.

3. An oxidation-reduction reaction or a redox reaction involves simultaneous reduction and oxidation processes.

The given chemical reaction, represents the combustion reaction of ethanol.

Since combustion reactions are redox reactions. Therefore, the given combustion reaction is an oxidation-reduction reaction.

4. According to the ideal gas equation: P.V =n.R.T

Volume (V) ∝ n (number of moles of gas)

Since the number of moles (n) of gaseous reactants is 3 and number of moles of gaseous (n) products is 2.

Therefore, the volume occupied by 3 moles of the reactant gaseous molecules will be more than 2 moles product gaseous molecules.

3 0

3 years ago