Answer:
Explanation:
1)<u> Convert the distance, 13.1 km to miles</u>
1 = 1 mi / 1.61 km
- 13.1 km [ 1 mi / 1.61 km ] = 8.1336 mi
2)<u> Use 6.2 mi/h as a converstion factor between distance and time</u>
- 8.1366 mi × 1 / [6.2 mi/h] = 1.3124 h
3) <u>Convert 1.3124 h to minutes</u>
- 1.3124 h × [ 60 min/h] = 78.7 min
Rounding to the nearest minutes (two significant figures):
Out of the two, the forces between water molecules and chromium and chloride ions is greater. This is proven by the fact that chromium chloride is slightly soluble in water, about 565 grams per liter.
In order for a substance to be soluble, the attraction of the ions to the water molecules must exceed the attraction between its own molecules and the water molecules.
Answer:
76.03 °C.
Explanation:
Equation:
C2H5OH(l) --> C2H5OH(g)
ΔHvaporization = ΔH(products) - ΔH (reactants)
= (-235.1 kJ/mol) - (-277.7 kK/mol)
= 42.6 kJ/mol.
ΔSvaporization = ΔS(products) - ΔS(reactants)
= 282.6 J/K.mol - 160.6 J/K.mol
= 122 J/K.mol
= 0.122 kJ/K.mol
Using gibbs free energy equation,
ΔG = ΔH - TΔS
ΔG = 0,
T = ΔH/ΔS
T = 42.6/0.122
= 349.18 K.
Coverting Kelvin to °C,
= 349.18 - 273.15
= 76.03 °C.
Answer:
c) An element is made up of all the same type of atom
Explanation:
Atoms are the smallest unit of an element that consists of protons, electrons and neutrons in its structure. An element is the smallest part of a chemical substance that cannot be disintegrated i.e. it cannot be broken down further.
Atoms and elements are different in many ways but they are connected in the sense that an element contains only one type of atoms. For example, aluminum element is made up of only aluminum atoms. Different atoms form a molecule but same atoms form an element.
The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the surface, probably by the use of a bleaching agent.
