A physical change<span> in a substance doesn't </span>change<span> what the substance is. In a </span>chemical change<span> where there is a </span>chemical reaction<span>, a new substance is formed and energy is either given off or absorbed.</span>
Answer:
there are 2 V's and there are 5 O's
Explanation:
First, consider the steps to heat the sample from 209 K to 367K.
1) Heating in liquid state from 209 K to 239.82 K
2) Vaporaizing at 239.82 K
3) Heating in gaseous state from 239.82 K to 367 K.
Second, calculate the amount of heat required for each step.
1) Liquid heating
Ammonia = NH3 => molar mass = 14.0 g/mol + 3*1g/mol = 17g/mol
=> number of moles = 12.62 g / 17 g/mol = 0.742 mol
Heat1 = #moles * heat capacity * ΔT
Heat1 = 0.742 mol * 80.8 J/mol*K * (239.82K - 209K) = 1,847.77 J
2) Vaporization
Heat2 = # moles * H vap
Heat2 = 0.742 mol * 23.33 kJ/mol = 17.31 kJ = 17310 J
3) Vapor heating
Heat3 = #moles * heat capacity * ΔT
Heat3 = 0.742 mol * 35.06 J / (mol*K) * (367K - 239.82K) = 3,308.53 J
Third, add up the heats for every steps:
Total heat = 1,847.77 J + 17,310 J + 3,308.53 J = 22,466.3 J
Fourth, divide the total heat by the heat rate:
Time = 22,466.3 J / (6000.0 J/min) = 3.7 min
Answer: 3.7 min
Answer is: (3) ionic and molecular.
Ionic compounds are made of ions held together with ionic bonds.
Ionic bond forms when a cation transfers its extra electron to an anion who needs it.
For example compound magnesium chloride (MgCl₂) has ionic bond (the electrostatic attraction between oppositely charged ions).
Magnesium (metal) transfers two electrons (became positive cation) to chlorine (became negative anion).
Molecular compounds are made up of molecules whose atoms are connected with covalent bonds.
Covalent bond is bond between nonmetals.
For example, molecule carbon monoxide CO has covalent bond.
Carbon (C) and oxygen (O) are nonmetals.
Carbon atom and oxygen atom are connected by a triple bond (six shared electrons in three bonding molecular orbitals) that is formed of two covalent bonds and one dative covalent bond.
