To find out how many molecules you have, you need to multiply the number of moles with Avogadros constant: 2.50 * 6.022 * 10²³ = 1.5055 * 10^24.
5F2 +2NH3 = N2f4 + 6HF
moles = mass/molar mass
mass =molar mass x mole
a) moles of Nh3 = 58.5/17 = 3.44 moles
the mole ratio of F2:NH3 = 5:2
the moles of F2 =3.44x5/2=8.6 moles
mass= 8.6 x 38 = 326.8 grams of F2
B) moles of Hf = 3.89/20 = 0.1945 moles
mole ratio NH3:Hf = 2:6
moles of NH3 = 0.1945 x2/6 = 0.0648 moles
mass =0.0648 x17 = 1.102 grams of NH3
C) moles of f2 = 217/38 =5.711 moles
mole ratio N2F6:F2 = 5:1
moles of N2F4 =5.711 x1/5 =1.142 moles
mass = 1.142 x104 = 118.77 grams of N2F4
Answer:
16.2 J
Explanation:
Step 1: Given data
- Specific heat of liquid bromine (c): 0.226 J/g.K
- Volume of bromine (V): 10.0 mL
- Initial temperature: 25.00 °C
- Final temperature: 27.30 °C
- Density of bromine (ρ): 3.12 g/mL
Step 2: Calculate the mass of bromine
The density is equal to the mass divided by the volume.
ρ = m/V
m = ρ × V
m = 3.12 g/mL × 10.0 mL
m = 31.2 g
Step 3: Calculate the change in the temperature (ΔT)
ΔT = 27.30 °C - 25.00 °C = 2.30 °C
The change in the temperature on the Celsius scale is equal to the change in the temperature on the Kelvin scale. Then, 2.30 °C = 2.30 K.
Step 4: Calculate the heat required (Q) to raise the temperature of the liquid bromine
We will use the following expression.
Q = c × m × ΔT
Q = 0.226 J/g.K × 31.2 g × 2.30 K
Q = 16.2 J
Hypothesis is your opinion/ your thinking and yes, scientists have hypothesis before they do an experiment
Hope this helps!
<span>Not all solids melt when they are heated. Some may undergo chemical changes as a result of heating. For example paper burns rather than melts</span>