Answer:
Pure water has an acidity of about 7 on the pH scale. -is a chemical property of pure water. Pure water has an acidity of about 7 on the pH scale
Asteroids This is a matter of knowing the definitions. Although the biggest hint is "Make up a belt between Mars and Jupiter" which should cause you to immediately think "Asteroid Belt". But let's look at the options and see what fits.
Comets - Mostly comprised of ice and dust. They're not "rocky", so this isn't a good choice.
Asteroids - Nothing the lecture describes conflicts with what an asteroid is, so this is the correct choice.
Meteor - Key thing here is a meteor is that a meteor is a small body that's burning up in the Earth's atmosphere, causing a streak of light. And that's not what the lecture is describing, so this is a bad choice.
Meteoroids - This is a body orbiting the sun, that will in the future become a meteor. And that's not something in a stable orbit between Mars and Jupiter. So this is also a bad choice.
CuSO4. 5H2O(s) → CuSO4(s) + 5 H2O(g)
Here, when we heat copper (II) sulphate pentahydrate, it will turn white in colour from blue colour.
There are several ways to visually represent compounds. For this particular organic compound, we can use the skeletal formula and the expanded formula. The skeletal makes use of lines to show which atoms are bonded to each other. The expanded formula shows the species of the atoms and their bonding with other atoms. I have attached the two representations.
Answer:
Exothermic
q = -8.03 kJ/g
Explanation:
<em>When 2 moles of Na(s) react with H₂O(l) to form NaOH(aq) and H₂(g) according to the following equation, 369 kJ of energy are evolved.</em>
The thermochemical equation is:
2 Na(s) + 2 H₂O(l) → 2 NaOH(aq) + H₂(g) ΔH = -369 kJ
Since the energy is evolved, the reaction is exothermic, which is why the enthalpy of the reaction (ΔH) is negative.
The heat released (q) per gram of Na(s) is (molar mass 22.98 g/mol):