<u>Answer:</u>
Pyrite leaves behind a green-black streak when it is rubbed against an unglazed porcelain plate as a part of the streak test process.
<u>Explanation:</u>
Different minerals produce different coloured streaks when rubbed against a white ceramic or porcelain streak plate. This streak test is done to identify the mineral and distinguish the same from other minerals that look similar in colour and texture.
It must be ensured that the test is done on clean and fresh specimens of the mineral and that there must be no contaminants. Pyrite specimens are usually brass-yellow colour but it leaves a green-black streak when the streak test is done.
To answer the questions,
(1) Activation energy is the amount of energy that is needed for the reaction to proceed, converting the reactant to products. The answer is letter B.
(2) The rate of chemical reaction normally increases as the reactant concentration is increased. The answer is letter C.
Answer: A physical property that will be the same regardless of the amount of matter. Extensive Properties: A physical property that will change if the amount of matter changes.
Answer:
Write a balanced chemical reaction:
N2 + 3H2 ==> 2NH3
Looking at the mole ratios in this balanced equation you can see it takes 3 moles H2 to make 2 moles NH3. So, next calculate the moles of NH3 represented by 1.80 g and then convert to moles of H2 needed:
moles of NH3 = 1.80 g x 1 mole/17 g = 0.106 moles NH3
Moles H2 needed = 0.106 moles NH3 x 3 moles H2/2 moles NH3 = 0.159 moles H2 needed
Grams H2 needed = 0.159 moles x 2 g/mole = 0.318 grams H2 needed
Explanation:
