Answer:
a. Endothermic
b. 26.37kJ/mol
Explanation:
a. As we can see, the temperature of the water is decreasing when the reaction is occurring, that means the reaction is absorbing heat and is endothermic
b. To find the enthalpy we must find the change in heat when 12.1g of KCl are dissolved. Using the equation:
Q = -m*ΔT*C
<em>Where Q is change in heat</em>
<em>m the mass of solution (250g + 12.1g = 262.1g)</em>
<em>ΔT is change in heat (17.1°C - 21.0°C = -3.9°C)</em>
<em>And C is specific heat of the solution (4.184J/g°C assuming is the same than the specific heat of water).</em>
<em />
Replacing:
Q = -262.1g*-3.9°C*4.184J/g°C
Q = 4277J = 4.28kJ
As reaction enthalpy is the change in heat per mole of reaction, we must find the moles of 12.1g of KCl:
<em>Moles KCl -Molar mass: 74.55g/mol-:</em>
12.1g KCl * (1 mol / 74.55g) = 0.1623 moles KCl
The reaction enthalpy us:
4.28kJ / 0.1623mol = }
<h3>26.37kJ/mol</h3>
<em />
Correct Answer: Mass of ore that contains 200 g of Ti is
617.28 g.
Reason:
Given: Ore contains 32.4% Ti by mass.
It implies that, 100 g of ore ≡ 32.4 g of Ti
Therefore, x g of ore ≡ 200 g of Ti
Thus, x =
Hence, mass of ore that contains 200 g of Ti is
617.28 g.
Answer:
B.) a cation that is smaller than the original atom
Explanation:
When the atoms of an element gains or loses electrons, it becomes charged. This charged atom is called an ION. An ion can either be a CATION or ANION depending on whether the atom loses electrons to become positively charged (cation) or gains electrons to become negatively charged (anion).
In this case, magnesium (Mg) atom gives up or loses electron(s) to become an ion, it will become positively charged and hence called a CATION. However, since it loses electrons in its atom, it becomes SMALLER than the original magnesium atom. This is because the electrons left in the atom becomes more attracted to the nucleus and decreases the ionic radius.
The carbon compounds are removed from the processes to serve as building blocks for other complex molecules.