Answer:
47 mL
Explanation:
By the image, the beaker graduation will from 45 from 50 mL, passing by 5 markings. So each mark has 1 mL. To read the volume, we have see the meniscus, which is the concave superficie of the liquid. The meniscus is above the second mark, so it passed 2 mL from the 45 line, the volume is 47 mL.
a. How many grams of Na20 are produced when 57.5 g of Na
reacts ?
b. If you have 18.0 g of Na, how many grams of O2 are
required for reaction?
c. How many grams of O2 are needed in a reaction that
produces 75.0 g of Na2O?
Answer:
Explanation:
a )
4Na(s) + O₂(g) - - 2Na₂O(s)
4 x 23g 32g 2x62
92 g of Na produces 124 g of Na₂O(s)
57.5 g of Na produces (124 / 92) x 57.5
= 77.5 g of Na₂O(s)
b )
92 g of Na requires 32 g of O₂
18 g of Na requires ( 32 / 92 ) x 18
= 6.26 g of O₂
c )
128 g of Na₂O(s) requires 32 g of O₂
75 g of Na₂O(s) requires ( 32 / 128 ) x 75
= 18.75 g of O₂
» A change in
means that a chemical reaction has occurred.
Answer:
C) the properties and identity of the reacting substances
Explanation:
took the test
Answer:
.....
Explanation:
Chemical changes occur when bonds between atoms are broken and new bonds form. As a result, new substances are produced. There are four signs that a chemical reaction has occurred: a change in color, a change in temperature, formation of a gas or formation of a precipitate.
continental polar air mass
continental tropical air mass
maritime polar air mass
maritime tropical air mass
Answer: continental tropical air mass
Explanation:
The continental tropical mass of air forms over the Texas. It forms in the interior of the subtropical continents at about 150 to 350 North to South latitude. They can be characterized by the dry and hot air masses due to the temperature and moisture present in their source region. The tropical air masses originate in the tropical regions (warm regions) these typically have low air pressure.
Answer:
2
Explanation:
continental tropical air mass
Answer:
Explanation:
Most hypothesis involves the statement of a problem. It is one of the easiest way to explain results from experiments and a pool of observation.
To create a hypothesis about how soil acidity affects the growth of blueberries, we must bear in mind the follow:
The dependent variable is the growth of the blueberries.
The independent variables are the chemicals we might be adding to the soil to increase the acidity.
Our best hypothesis would be "how the addition of different pH of acid to soil affects the growth of blueberries".
Answer:
The magnesium reacted with the oxygen in the air.
Explanation:
For argument’s sake, let’s say that the mass of magnesium oxide was 3 g and that of the oxide was 5 g.
The reaction was
magnesium + oxygen ⟶ magnesium oxide
Mass: 3 g 5 g
Mass of oxygen = 5 g – 3 g = 2 g
The 3 g of magnesium must have combined with 2 g of oxygen to form 5 g of magnesium oxide.