Answer:
- <u><em>1.7 × 10³ kg of ore.</em></u>
Explanation:
Call X the amount of aluminum ore mined to produce 1.0 × 10³ kg the aluminum metal.
Then, taking into account the yield of the reaction (82 % = 0.82) and the percent of aluminun in the ore (71% = 0.71), you can write the following equation:
- X × 71% × 82% = 1.0 × 10³ kg
↑ ↑ ↑ ↑
(mass of ore) (% of Al in the ore) (yield) ( Al metal to obtain)
You must just simplify, solve and compute:
- X = 1,000 / (0.71 × 0.82) = 1,000 / 0.5822 = 1,717.6 Kg
Round to two significant figures; 1,700 kg = 1.7 × 10³ kg of ore ← answer.
Answer:
235 g
Explanation:
From the question;
- Volume is 400.0 mL
- Molarity of a solution is 4.25 M
We need to determine the mass of the solute K₂CO₃,
we know that;
Molarity = Number of moles ÷ Volume
Therefore;
First we determine the number of moles of the solute;
Moles = Molarity × volume
Moles of K₂CO₃ = 4.25 M × 0.4 L
= 1.7 moles
Secondly, we determine the mass of K₂CO₃,
We know that;
Mass = Moles × Molar mass
Molar mass of K₂CO₃, is 138.205 g/mol
Therefore;
Mass = 1.7 moles × 138.205 g/mol
= 234.9485 g
= 235 g
Thus, the mass of K₂CO₃ needed is 235 g
Answer:observation
Explanation:
this is the answer because they saw it they know it is there. the flowers are pink and they saw that that’s what an observation is so the answer is an OBSERVATION
Answer:
FALSE
Explanation:
Br is <em>bromine</em> with atomic number 35, mass number of 79.904 and belongs to the group 7 elements known as the halogens.
Ga is <em>gallium</em> with atomic number 31, mass number of 69.72 and belongs to the alkaline earth metal i.e the group 3 elements.
From the above and in terms of their mass number, it is evident that Br is the larger element compared to Ga which is lesser than Br. Hence the statement is FALSE
