Answer:
a) the element belongs to group 2
b) see image attached
c) Magnesium
d) X3N2
Explanation:
Any ion with the formula X^2+ was derived from group 2 elements. The group two element found in period 3 is magnesium alone.
Since the nitride ion has a valency of -3 and X^2+ has a valency of +2 , then a compound formed between X^2+ and the nitride ion will have the formula X3N2.
Answer:
The mass of a sample of iron that has had 300 J applied to it and heats up from 20 degrees Celsius to 40 degrees Celsius is 32.61 grams.
Explanation:
Calorimetry is the measurement and calculation of the measurement of heat changes exchanged by a body or a system produced in physical and chemical processes.
The sensible heat of a body is the amount of heat received or transferred by a body to produce a change in temperature but without a change in physical state.
The sensible heat in a constant pressure is calculated by:
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 temperature variation (ΔT=Tfinal - Tinitial)
In this case:
Replacing:
300 J= 0.46 * m* (40 - 20) C
Solving:
300 J= 0.46 * m* 20 C
m= 32.61 g
Answer: The enthalpy change is 34.3 kJ
Explanation:
The conversions involved in this process are :
Now we have to calculate the enthalpy change.
where,
= enthalpy change = ?
m = mass of water = 72.0 g
= specific heat of ice =
= specific heat of liquid water =
n = number of moles of water =
= enthalpy change for fusion = 6010 J/mole
Now put all the given values in the above expression, we get
(1 KJ = 1000 J)
Therefore, the enthalpy change is 34.3 kJ