Answer : The specific heat (J/g-K) of this substance is, 0.780 J/g.K
Explanation :
Molar heat capacity : It is defined as the amount of heat absorbed by one mole of a substance to raise its temperature by one degree Celsius.
1 mole of substance releases heat = 92.1 J/K
As we are given, molar mass of unknown substance is, 118 g/mol that means, the mass of 1 mole of substance is, 118 g.
As, 118 g of substance releases heat = 92.1 J/K
So, 1 g of substance releases heat = 
Thus, the specific heat (J/g-K) of this substance is, 0.780 J/g.K
Answer:
1.26 M
Explanation:
The ion nitrate is NO₃⁻ and the Barium is from group 2 so it forms the ion Ba²⁺, so the barium nitrate has the formula: Ba(NO₃)₂. The molar masses are: Ba: 137 g/mol, N = 14 g/mol, O = 16 g/mol, so the molar mass of barium nitrate is:
137 + 2x(14 + 3x16) = 199 g/mol
The number of moles is the mass divided by the molar mass, so:
n = 25.1/199 = 0.126 mol of Ba(NO₃)₂
In 1 mol of the salt, there are 2 moles of NO₃⁻, so the number of moles of nitrate is 0.252 mol. Nitrates formed with ammonium (that can react when the solid dissolves) and with elements from group 1 and 2 are completely soluble in water. So, the moles of nitrate will remain 0.252 mol.
The molarity is the number of moles divided by the volume (0.2 L):
[NO₃⁻]= 0.252/0.2 = 1.26 M
Answer:
18.75 milligrams of active ingredient is the recommended dose for a child weighing 36–47 lbs .
Explanation:
Recommended dose of an antihistamine for a child weighing 36–47 lbs = 1.50 tsp
1 table spoon of antihistamine has 12.5 mg per 5 mL of dose.
Amount of dose in 1 teaspoon = 
Volume of 1 tsp = 5 ml
Volume of 1.50 teaspoon = 
Amount of antihistamine in 7.50 mL :
18.75 milligrams of active ingredient is the recommended dose for a child weighing 36–47 lbs .
When an atom gains an electron it becomes a negatively charged ion. When an atom looses an electron it becomes positively charged because the number of positively charged protons.
Hope this helps
Answer: The mass of ice you would need to add to bring the equilibrium temperature of the system to 300 K is 
kg.
Explanation:
We know that relation between heat energy and specific heat is as follows.
q = 
As density of water is 1 kg/L and volume is given as 400,000 L. Therefore, mass of water is as follows.
Mass of water = Volume × Density
= 
= 400,000 kg
or, = 
g (as 1 kg = 1000 g)
Specific heat of water is 4.2 J/gm K. Therefore, change in temperature is as follows.
= 305 K - 273 K
= 32 K
Now, putting the given values into the above formula and calculate the heat energy as follows.
q =
= 
= 
J
or, = 
kJ
According to the enthalpy of melting of ice 333 kJ/Kg of energy absorbed by by 1 kg of ice. Hence, mass required to absorb energy of kJ is calculated as follows.
Mass = 
= kg
Thus, we can conclude that the mass of ice you would need to add to bring the equilibrium temperature of the system to 300 K is kg.
