Answer:
CaF2
Explanation:
Calcium fluoride is a solid formed by the chemical combination of Calcium (Ca) and Fluorine (F). Two molecules of fluorine (F2) and one molecule of Calcium (Ca) are needed to form the Calcium Fluoride molecule.
An ionic bond is formed between the Calcium and Fluorine atoms i.e. electrons are transferred from calcium atoms to fluorine atoms. The calcium ion is a cation with formula; Ca2+ while fluorine is an anion with formula; F-. Hence, it takes two molecules of Fluorine ion (F-) to form a relatively stable and neutral molecule with 1 molecule of Calcium ion (Ca2+).
Answer:
\frac{dh}{dt}_{h=2cm} =\frac{40}{9\pi}\frac{cm}{2}
Explanation:
Hello,
The suitable differential equation for this case is:
As we're looking for the change in height with respect to the time, we need a relationship to achieve such as:
Of course, 
.
Now, since the volume of a cone is 
and the ratio 
or 
, the volume becomes:
We proceed to its differentiation:
Then, we compute 
Finally, at h=2:
Best regards.
Answer:
449730.879 cal/g
Explanation:
Given data:
Mass of sample = 4.9 g
Change in temperature = 2.08 °C (275.23 k)
Heat capacity of calorimeter = 33.50 KJ . K⁻¹
Solution:
C(candy) = Q/m
Q = C (calorimeter) × ΔT
C(candy) = C (calorimeter) × ΔT / m
C(candy) = 33.50 KJ . K⁻¹ × 275.23 K / 4.90 g
C(candy) = 9220.205 KJ / 4.90 g
C(candy) = 1881.674 KJ / g
It is known that,
1 KJ /g = 239.006 cal/g
1881.674 × 239.006 = 449730.879 cal/g
