Answer : The molal freezing point depression constant of X is 
Explanation : Given,
Mass of urea (solute) = 5.90 g
Mass of X liquid (solvent) = 450.0 g
Molar mass of urea = 60 g/mole
Formula used :

where,
= change in freezing point
= freezing point of solution = 
= freezing point of liquid X= 
i = Van't Hoff factor = 1 (for non-electrolyte)
= molal freezing point depression constant of X = ?
m = molality
Now put all the given values in this formula, we get
![[0.4-(-0.5)]^oC=1\times k_f\times \frac{5.90g\times 1000}{60g/mol\times 450.0g}](https://tex.z-dn.net/?f=%5B0.4-%28-0.5%29%5D%5EoC%3D1%5Ctimes%20k_f%5Ctimes%20%5Cfrac%7B5.90g%5Ctimes%201000%7D%7B60g%2Fmol%5Ctimes%20450.0g%7D)

Therefore, the molal freezing point depression constant of X is 
Answer:
SiH4 is nonpolar and BBr3 is nonpolar and SiF4 is nonpolar.
Explanation:
SiH4 is a non-polar compound. Though the Si–H bonds are polar, as a result of different electronegativities of Si and H. However, as there are 4 electron repulsions around the central Si atom, the polar bonds are arranged symmetrically around the central atom having a tetrahedral shape hence they cancel out making the compound nonpolar.
SiF4 is a nonpolar molecule because the fluorine atoms are arranged symetrically around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out just like in SiH4.
The 3 bromine atoms all lie in the same plane thus the geometry of the compound will be trigonal planar. The BBr3 will be non polar because the three B-Br bonds will cancel out each others' dipole moment given that they are in the same plane.
The third launch ( with 300 N force) had the greatest acceleration of the tennis ball
<h3>Further explanation </h3>
Newton's 2nd law explains that the acceleration produced by the resultant force on an object is proportional and in line with the resultant force and inversely proportional to the mass of the object
∑F = m. a

F = force, N
m = mass = kg
a = acceleration due to gravity, m / s²
From the above equation it has been shown that the force acting on the object is directly proportional to its acceleration, so <em>the greater the force exerted on the object, the greater the acceleration of the object produced.</em>
Answer:
The first row of elements fits in period <u>6</u>, after the element <u>lanthanum (La)</u>. The second row of elements fits in period <u>7</u>, after the element <u>actinium (Ac). </u>
I hope this helps!
Answer:iron and oxygen combining to make rust. vinegar and baking soda combining to make sodium acetate, carbon dioxide and water
Explanation: