Answer:
The correct answer is control group.
Explanation:
A group used in a study or in an experiment, which does not get treatment by the scientists and is used as a foundation to determine the functions of the other tested subjects is known as the control group. The control group is only found in an experimental investigation.
The group in an experiment, which gets the variable being examined is known as an experimental group. The comparison of an experimental group is done with a control group in order to find the answers in an experiment.
The reaction between HCl and NaHCO3 will be;
HCl + NaHCO3 = NaCl + CO2 + H2O
The relative formula mass of NaHCO3 is 84 g/mol
Moles of NaHCO3 in 2 g will be; 2/84 =0.0238 moles
The mole ratio of HCl and NaHCO3 is 1;1
Thus, the number of moles of HCl is 0.0238 moles
The volume of HCl will be;
= 0.0238 moles/0.2
= 0.119 liters or 119 cm³
Answer:
Thermal decomposition
Explanation:
Calcium carbonate can be broken down by heating. The following equation represents this chemical change.
CaCO₃(s) ⇒ CaO(s) + CO₂(g)
The scientific term for this process is thermal decomposition.
- Thermal refers to the fact that heat is required.
- Decomposition refers to the kind of reaction in which a big substance breaks down into smaller substances.
Answer : The molar mass of hemoglobin is, 
Explanation : Given,
Molar mass of iron = 55.85 g/mol
0.349 % Fe by mass that means 0.349 grams of Fe present in 100 grams of hemoglobin.
or,

Now put all the given values in this formula, we get:


Thus, the molar mass of hemoglobin is, 