Answer:K2X
Explanation: Valency can be defined as the combining power of an element. It is the valency that dictates the value an element will have when writing a chemical formula for its compound.
MgX is a compound of magnesium and an element X. The valency of magnesium in most of its compound is +2. Now for the 2 to have been absent in the chemical formula, this shows that the element X itself have a valency if -2 for the valencies of both to have canceled out.
Now considering the element potassium, it is an alkaline metal belonging to group 1 of the periodic table. Hence, it is expected that it has a valency of +1
Forming a compound with element X means there would be an exchange of valencies between the two. We have established that x has a valency of -2. The formula of the compound thus formed by exchanging the valencies of both element would be K2X
To solve this problem we can use following equation.
v =u + at
Where v is the final velocity (m/s), u is the initial velocity (m/s), a is the acceleration (m/s²) and t is the time taken (s).
v = 7 m/s
u = 4 m/s
a = ?
t = 5 s
By applying the equation, we can get
7 m/s = 4 m/s + a x 5 s
3 m/s = a x 5 s
a = 0.6 m/s²
Hence, the acceleration is 0.6 m/s² towards north.
Answer is "C".
Answer:
0.001 M OH-
Explanation:
[OH-] = 10^-pOH, so
pOH + pH = 14 and 14 - pH = pOH
14 - 11 = 3
[OH⁻] = 10⁻³ ; [OH-] = 0.001 M OH-
Bond angle of ch4 = 109.5
Answer:
26.95 %
Explanation:
Air contains the highest percentage of oxygen and nitrogen gases. Magnesium then combines with both of the gases:
Firstly, find the total number of moles of magnesium metal:
Let's say that x mol react in the first reaction and y mol react in the second reaction. This means:
According to stoichiometry, we form:
Multiplying moles by the molar mass of each substance will yield mass. This means we form a total of:
The total mass is given, so we have our second equation to solve:
We have two unknowns and two equations, we may then solve:
Express y from the first equation:
Substitute into the second equation:
Moles of nitride formed:
Convert this to mass:
Find the percentage:
