Answer:
69.7 mL ≅ 70 mL
Explanation:
The chemical reaction between hydrobromic acid (HBr) and lithium metal (Li) produces lithium bromide (LiBr) and hydrogen (H₂) according to the following equation:
2HBr(aq) + 2Li(s) → 2LiBr(aq) + H₂(g)
Thus, 2 moles of HBr reacts with 2 moles of Li. So, the stoichiometric ratio is 1:1 (1 mol HBr reacts with 1 mol Li).
We convert the mass of Li to moles by using the molar mass (MM) of LiBr:
MM(LiBr) = 6.9 g/mol + 79.9 g/mol = 86.8 g/mol
moles of Li(s) = mass/MM(LiBr) = 19.4 g/86.8 g/mol = 0.223 moles Li(s)
Now, we can divide the moles of Li into the molarity of the HBr solution to obtain the volume in liters wee need to add:
V = moles Li(s)/M = (0.223 mol)/(3.2 mol/L) = 0.0697 L
0.0697 L x 1000 mL/1 L = 69.7 mL ≅ 70 mL
Therefore, 70 mL of 3.2 M HBr are needed to entirely dissolve the metal.
The sun has been up for several hours, and it has been shining on these trees. What can the trees do because they are in sunlight? What does this mean for the number of energy storage molecules in the trees?
The trees can . . .
a give off carbon to the air. Giving off carbon allows them to make energy
storage molecules.
b give off carbon to the air. Giving off carbon uses up energy storage
molecules.
c take in carbon from the air. The carbon is used to make energy storage
molecules.
d take in carbon from the air. The carbon is used to break down energy storage molecules.
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2. These goats are eating grass on a sunny day. What is happening to the carbon in the air around the living things on the mountain? Is carbon moving into the air, moving out of the air, or both?
a Carbon is only moving into the air; it is not moving out of the air. b Carbon is moving into the air and out of the air at the same time. c Carbon is not moving into the air; it is only moving out of the air. d With this information, there is no way to know for sure.
Answer:
1. C. take in carbon from the air. The carbon is used to make energy storage
molecules.
2. b Carbon is moving into the air and out of the air at the same time
Explanation:
Question 1:
Trees are plants, which are autotrophic organisms i.e. set of organisms that are capable of producing their own food via a process called PHOTOSYNTHESIS. This photosynthetic process produces sugars (glucose) in the presence of SUNLIGHT. According to this question, the sun has been up for several hours, and has been shining on these trees. This means that the trees can take in carbo dioxide (CO2) in order to perform the process of photosynthesis. Also, the number of energy storage molecules in the trees (ATP) will INCREASE.
What can the trees do because they are in sunlight? What does this mean for the ?
The trees can take in carbon from the air, the carbon is used to make energy storage molecules and Carbon is moving into the air and out of the air at the same time when goats are eating grass on a sunny day.
What is photosynthesis?Photosynthesis is a process by which plants prepare their own food in the form of carbohydrates in the presence of sunlight.
Plants absorbs carbon dioxide from the atmosphere and in the presence of sunlight with the water molecules prepare their food in the form of carbohydrates to store energy and releases oxygen to the atmosphere, and this process is known as photosynthesis.If goats are eating grass on a sunny day then in this condition, carbon dioxide exhaled by the goats is absorbed by the plants and oxygen releases to the environment by the plants and inhaled by goats.Hence, for first point correct option is (c) and for second point correct option is (b).
To know more about atmospheric carbondioxide, visit the below link:
https://brainly.com/question/25385913
