Answer:
All except ch4
Explanation:
NH3 N H 3 and HF can form hydrogen bonds as they have a hydrogen atom bonded to fluorine and nitrogen atoms.
Answer:
The given compound cannot be cocaine.
Explanation:
The chemist can comment on the nature of compound being cocaine or not from the depression in freezing point.
Depression in freezing point of is related to molality as:
Depression in freezing point = Kf X molality
Where
Kf = cryoscopic constant = 4.90°C/m
depression in freezing point = normal freezing point - freezing point of solution
depression in freezing point = 5.5-3.9 = 1.6°C
1.6°C = 4.90 X molality
we know that:
therefore
moles = 0.327X0.008 = 0.00261 mol
The molar mass of cocaine is 303.353
So the given compound cannot be cocaine.
Answer is: A. test and determine the pH values of unknown solutions.
Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations (pH or pOH values).
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄). Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Another example is methyl orange. It is red colour in acidic solutions and yellow colour in basic solutions.
Answer:
It will be reported too low.
Explanation:
To measure the specific heat of the metal (s), the calorimeter may be used. In it, the metal will exchange heat with the water, and they will reach thermal equilibrium. Because it can be considered an isolated system (there're aren't dissipations) the total amount of heat (lost by metal + gained by water) must be 0.
Qmetal + Qwater = 0
Qmetal = -Qwater
The heat is the mass multiplied by the specific heat multiplied by the temperature change. If c is the specific heat of the water:
m_metal*s*ΔT_metal = - m_water *c*ΔT_water
s = -m_water *c*ΔT_water / m_metal*ΔT_metal
So, if m_water is now less than it was supposed to be, s will be reported too low, because they are directly proportional.
Answer:
A - NaCl is a product
D - Cl2 is a gas
Explanation:
Based on the chemical reaction;
2Na(s) + Cl2(g) → 2NaCl2
- Sodium metal reacts with chlorine gas to form sodium chloride. Sodium is in solid state, chlorine is in gaseous state and Sodium chloride is in solid state.
- In the chemical reaction, sodium and chlorine are reactants while sodium chloride is the product.
- Additionally the chemical reaction above is balanced so as to obey the law of conservation of mass.
