Equation a. C3H8(g) + O2(g) → CO2(g) + H2O(g) + 2220 kj
is endothermic. + 2220 kj
Equation b. 2 Na(s) + Cl2(g) → 2 NaCl(s) + 819kJ
is also endothermic since the overall energy change is positive. + 819kJ
The equation c. PCl5(g) + 67kj → PCl3(g) + Cl2(g) is endothermic since it requires anergy to proceed.
Answer:
![\boxed {\boxed {\sf 0.80 \ mol\ F}}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%200.80%20%5C%20mol%5C%20F%7D%7D)
Explanation:
We are asked to find how many moles are in 4.8 × 10²³ fluorine atoms. We convert atoms to moles using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of fluorine.
We will convert using dimensional analysis and set up a ratio using Avogadro's Number.
![\frac {6.022 \times 10^{23} \ atoms \ F}{ 1 \ mol \ F}](https://tex.z-dn.net/?f=%5Cfrac%20%7B6.022%20%5Ctimes%2010%5E%7B23%7D%20%5C%20atoms%20%5C%20F%7D%7B%201%20%5C%20mol%20%5C%20F%7D)
We are converting 4.8 × 10²³ fluorine atoms to moles, so we multiply the ratio by this number.
![4.8 \times 10^{23} \ atoms \ F *\frac {6.022 \times 10^{23} \ atoms \ F}{ 1 \ mol \ F}](https://tex.z-dn.net/?f=4.8%20%5Ctimes%2010%5E%7B23%7D%20%5C%20atoms%20%5C%20F%20%2A%5Cfrac%20%7B6.022%20%5Ctimes%2010%5E%7B23%7D%20%5C%20atoms%20%5C%20F%7D%7B%201%20%5C%20mol%20%5C%20F%7D)
Flip the ratio so the units of atoms of fluorine cancel each other out.
![4.8 \times 10^{23} \ atoms \ F *\frac { 1 \ mol \ F}{6.022 \times 10^{23} \ atoms \ F}](https://tex.z-dn.net/?f=4.8%20%5Ctimes%2010%5E%7B23%7D%20%5C%20atoms%20%5C%20F%20%2A%5Cfrac%20%7B%201%20%5C%20mol%20%5C%20F%7D%7B6.022%20%5Ctimes%2010%5E%7B23%7D%20%5C%20atoms%20%5C%20F%7D)
![4.8 \times 10^{23} *\frac { 1 \ mol \ F}{6.022 \times 10^{23} }](https://tex.z-dn.net/?f=4.8%20%5Ctimes%2010%5E%7B23%7D%20%20%2A%5Cfrac%20%7B%201%20%5C%20mol%20%5C%20F%7D%7B6.022%20%5Ctimes%2010%5E%7B23%7D%20%7D)
Condense into 1 fraction.
![\frac { 4.8 \times 10^{23} }{6.022 \times 10^{23} } \ mol \ F](https://tex.z-dn.net/?f=%5Cfrac%20%7B%204.8%20%5Ctimes%2010%5E%7B23%7D%20%7D%7B6.022%20%5Ctimes%2010%5E%7B23%7D%20%7D%20%5C%20mol%20%5C%20F)
Divide.
![0.7970773829 \ mol \ F](https://tex.z-dn.net/?f=0.7970773829%20%5C%20mol%20%5C%20F)
The original measurement of atoms has 2 significant figures, so our answer must have the same. For the number we found, that is the hundredths place. The 7 in the thousandths tells us to round the 9 in the hundredths place up to a 0. Then, we also have to round the 7 in the tenths place up to an 8.
![0.80 \ mol \ F](https://tex.z-dn.net/?f=0.80%20%5C%20mol%20%5C%20F)
4.8 × 10²³ fluorine atoms are equal to <u>0.80 moles of fluorine.</u>
Answer:
covalent bond
Explanation:
a covalent bond happens between two nonmetals
a ionic bond happens between a metal and a non metal
CO2 is a bond between carbon and oxygen
carbon and oxygen are both non metals therefore CO2 is a covalent bond
Explanation:
Given that,
Mass number, A = 302
Atomic number, Z = 119
We know that, atomic number = no of protons
Protons = 119
Mass no. = No. of neutrons + No. of protons
302 = No. of neutrons + 119
No. of neutrons = 302 - 119
= 183
No. of electrons = No. of protons
= 119