Answer:
A base is a substance that can donate a hydroxide ion.
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Some forms of transportation are meant for small short trips while other forms of transportation are meant for big long trips
The energy required to melt 20 kg of ice at 0°C is 6.68 kJ.
The enthalpy change for melting of an ice is called the enthalpy of fusion. Its value is 6.02 kJ/mol. This means for every mole of ice we must apply 6.02 kJ of heat for melting. The calculation of heat is done by following equation.
q = n×ΔH
- q is heat
- n is number of moles
in this problem we need to calculate heat needed to melt 20grams of ice at 0°C .
Calculation of moles of water,
Number of moles of water (n) = given mass/ molar mass = 20g/18.02g/mol
Number of moles of water (n) = 1.109 mole
heat or energy required = q = n×ΔH = 1.109 mole× 6.02 kJ/mol = 6.68 kJ
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Strategy: with the measures you can determine the volume of the plate of aluminum. Then you can use the density of aluminum to calculate the mass.
With the mass of aluminum and its atomic mass you can find the number of moles and thereafter the number of atoms.
Finally divide the cost by the number of atoms to find the cost of one single atom.
Let's do it.
Volume of aluminum plate, V: 0.0112 in* 4.83 in* 2.60 in * [2.54 cm/in]^3 = 2.305 cm^3
Density of aluminum (from Wikipedia), d = 2.70 g/cm^3
mass, m = d*V = 2.305 cm^3 * 2.70 g/ cm^3 = 6.22 g
Atomic mass of aluminum (from Wikipedia), am = 27 g / mol
Number of moles, n = m/am = 6.22 g / 27 g / mol = 0.23 mol
Number of atoms = n*Avogadro constant = 0.23 mol * 6.022 * 10^23 atoms/mol = 1.39*10^23
Cost per atom = cost of the can / number of atoms =$ 0.05 /1.39*10^23 atoms = 3.60 * 10^ - 25 $/atom