Answer : The specific heat of the substance is 0.0936 J/g °C
Explanation :
The amount of heat Q can be calculated using following formula.

Where Q is the amount of heat required = 300 J
m is the mass of the substance = 267 g
ΔT is the change in temperature = 12°C
C is the specific heat of the substance.
We want to solve for C, so the equation for Q is modified as follows.

Let us plug in the values in above equation.


C = 0.0936 J/g °C
The specific heat of the substance is 0.0936 J/g°C
Answer:
3,200 joules
Explanation:
q = mcΔT = (250.0 g)(0.128 j/g°C)(100°C -25°C) = 3,200 joules
<span>Xe = VIII = 8 valence electrons
F = VII = 4 (7 ve) = 28 valence electrons</span>
total ve = 8 + 28 = 36 ve
<span>36 - 4(2) = 28 ve
(there are 2 electrons in each bond x 4 bonds)</span>
<span>28 - 4(6) = 4
(We assign the remaining electrons to F atoms)</span>
<span>4 - 2(2) = 0
(Therefore 4 electrons left => we have 2 lone pairs)</span>
The steric number = No. of
σ bonds + #lone pairs
= 4 σ bonds + 2 lone pairs
= 6 => d²sp³ (6 hybrid orbitals)
<span>4 bonds + 2 lone pairs
=> square planar</span>