Answer:
D. -1882J
Explanation:
We can solve the energy released in a chemical reaction in an aqueous medium using the equation:
Q = -m*C*ΔT
<em>Where Q is energy (In J),</em>
<em>m is mass of water (45.00g)</em>
<em>C is specific heat of water (4.184J/g°C)</em>
<em>And ΔT is change in temperature (25.00°C - 15.00°C = 10.00°C)</em>
<em />
Replacing:
Q = -45.00*4.184J/g°C*10.00°C
Q = -1882J
Right answer is:
<h3>D. -1882J</h3>
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Answer:
In this phenomenon we talk about ideal gases, that is why in these equations the constant is the number of moles and the constant R, which has a value of 0.082
Explanation:
The complete equation would have to be P x V = n x R x T
where n is the number of moles, and if it is not clarified it is because they remain constant, as the question was worded.
On the other hand, the symbol R refers to the ideal gas constant, which declares that a gas behaves like an ideal gas during the reaction, and its value will always be the same, which is why it is called a constant. The value of R = 0.082.
The ideal gas model assumes that the volume of the molecule is zero and the particles do not interact with each other. Most real gases approach this constant within two significant figures, under pressure and temperature conditions sufficiently far from the liquefaction or sublimation point. The real gas equations of state are, in many cases, corrections to the previous one.
The universal constant of ideal gases is not a fundamental constant (therefore, choosing the temperature scale appropriately and using the number of particles, we can have R = 1, although this system of units is not very practical)
Answer:
An increase in entropy
Explanation:
In ice, the molecules are very well ordered because of the H-bonds. As ice melts, the intermolecular forces are broken (requires energy), but the order is interrupted (so entropy increases). Water is more random than ice, so ice spontaneously melts at room temperature.
Just think about this rationally. Melting ice (or anything) will require heat put in (this is called the latent heat of fusion), so you automatically know that the change in enthalpy is going to be positive. In order to make the reaction spontaneous, delta G, the Gibbs free energy has to be negative. So now look at the formula Delta(G) = Delta(H) - T*Delta*(S). If you know that g is negative, and H is positive, then it is only possible if -T*Delta(S) is negative. If that is positive, then Delta(S) has to be positive. So theres your answer :). An increase in entropy
At the same temperature, steam burns are often more severe that water burns because of water's high HEAT OF VAPORIZATION.
Water possesses high heat of vaporization. The heat of vaporization refers to the amount of heat that is needed to convert a unit mass of water to gas. After getting to the boiling point, a lot of heat is still needed to be absorbed by a boiling water before it can be converted to the gaseous form. Thus, the heat that is inherent in the steam is greater than that which is found in the boiling water, that is why the steam causes more damages.
Answer:
Molar mass
Explanation:
This is a counting unit which represents the mass in grams of a substance that make up one mole of the substance. This mass is calculated as follows:
Molar mass = Mass/ Number of moles
Units: grams/mol
