Answer:
A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher
D. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.
Explanation:
Sand absorbs water and stores it. The sunlight causes the water to evaporate but sand can hold some of the water inside it. This results in increase in mass of the sand. The mass of sand before and after the water evaporation can be different.
The temperature change is 23 °C.
<em>q = mC</em>Δ<em>T</em>
Δ<em>T</em> = <em>q</em>/(<em>mC</em>)
<em>m</em> = 355 g
∴ Δ<em>T</em> = (34 000 J)/(355 g × 4.184 J·°C⁻¹g⁻¹) = 23 °C
<em>Note</em>: The answer can have only <em>two significant figures</em> because that is all you gave for the amount of heat absorbed.
1) If the arrangement is symmetrical and the arrows are of equal length the molecule is nonpolar
2) If the arrows are of different lengths and if they do not balance each other the molecule is polar
3) If the arrangement is asymmetrical the molecule is polar
Answer:
Sodium + Water = Sodium Hydroxide + Dihydrogen
Explanation:
eaction of sodium with water
Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic.