The minerals that one might be examining if you place some hydrochloric acid on a sample and it fizzes are Calcite and Dolomite.
Calcite and dolomite are very similar minerals. Both have the same hardness, the same rhombohedral cleavage, and are found in identical geologic settings. The best way to tell one from the other is the acid test; A drop of 1 M HCl on calcite produces an instant , obvious Fizz; a drop on dolomite produces slow or no obvious bubbling.
Answer:
= -457.9 kJ and reaction is product favored.
Explanation:
The given reaction is associated with 2 moles of 
Standard free energy change of the reaction () is given as:
, where T represents temperature in kelvin scale
So, 
So, for the reaction of 1.57 moles of , 
As, is negative therefore reaction is product favored under standard condition.
thermal contact
When heat flows from one object or substance to another it is in contact with, the objects or substances are said to be in thermal contact. The state where objects in thermal contact with each other reach the same temperature, no heat flows between them.
I suspect this question should read "How long does a red blood cell live." A red blood cell lives for between 100 and 120 days. It takes 7 days for a new red blood cell to develop from stem cells. Stem cells are similar to base cells. They can also be seen as a general template from which specialized cells are made. Stem cells can be taken from a newborn baby's umbilical chord or extracted from an adult blood donor's blood.This
Answer:
b. 54.9%
Explanation:
An emerald gemstone has the formula Be₃Al₂Si₁₆O₁₈. We can find the mass of each element in 1 mole of Be₃Al₂Si₁₆O₁₈ by multiplying the molar mass of the element by its atomicity.
Be: 3 × 9.01 g = 27.03 g
Al: 2 × 26.98 g = 53.96 g
Si: 16 × 28.09 g = 449.4 g
O: 18 × 16.00 g = 288.0 g
Total mass = 818.4 g
The mass percentage of silicon is:
(449.4 g / 818.4 g) × 100% = 54.91%
