Answer:
If 700 g of water at 90 °C loses 27 kJ of heat, its final temperature is 106.125 °C
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
In this way, between heat and temperature there is a direct proportional relationship (Two magnitudes are directly proportional when there is a constant so that when one of the magnitudes increases, the other also increases; and the same happens when either of the two decreases .). The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature, ΔT= Tfinal - Tinitial
In this case:
- Q= 27 kJ= 27,000 J (being 1 kJ=1,000 J)
- m=700 g
- ΔT= Tfinal - Tinitial= Tfinal - 90 °C
Replacing:
Solving:
16.125 °C= Tfinal - 90 °C
Tfinal= 16.125 °C + 90 °C
Tfinal= 106.125 °C
<u><em>If 700 g of water at 90 °C loses 27 kJ of heat, its final temperature is 106.125 °C</em></u>
The mass of piece of sterling silver jewelry is 33.24 g. It contains 92.5% silver Ag by mass. Since, sterling silver is an alloy of Ag-Cu thus, percentage of Cu will be:
% Cu=100-92.5=7.5%
Thus, mass of copper will be:
Molar mass of Cu is 63.546 g/mol, thus, number of moles of Cu can be calculated as follows:
Here, m is mass and M is molar mass.
Putting the values,
Now, in 1 mole of Cu there are 
thus, in 0.03923 mol, number of Cu atoms will be:
Thus, number of atoms of Cu will be
.
Answer:
- Acetic acid (CH₃COOH) and hydronium ion (H₃O⁺)
Explanation:
Hello,
In this case, based on the acid-base theory which states that acids are known as H⁺ donors, if we consider the direct reaction:
It is clear that the acetic acid is the first H⁺ donor as it losses one H⁺ to turn into the acetate ion. Moreover, if we consider the inverse reaction:
It is also clear that the hydronium ion is the second H⁺ donor as it losses one H⁺ to turn into water.
Best regards.
C.
Because the spinal cord functions primarily in the transmission of neural signals between the brain and the rest of the body
Answer:
The frequency is 
Explanation:
From the question we are told that
The energy required to ionize boron is 
Generally the ionization energy of boron pre atom is mathematically represented as
Here 
is the Avogadro's constant with value 
So
=> 
Generally the energy required to liberate one electron from an atom is equivalent to the ionization energy per atom and this mathematically represented as
=> 
Here h is the Planks constant with value 
So
=>
