Answer:
element
Explanation:
Elements are pure substances with only one kind of atom
Answer:
ΔH = +26.08 kJ/mol
Explanation:
The change in enthalpy (ΔH) is given in J/mol, and can be calculated for dissolution by the equation:
ΔH = m(water)*Cp*ΔT/n(solute)
The mass of water is the density multiplied by the volume
m = 1g/mL * 25.0mL = 25.0 g
The number of the moles is the mass divided by the molar mass. Knowing the molar masses of the elements:
N = 14 g/mol x 2 = 28
H = 1 g/mol x 4 = 4
O = 16 g/mol x 3 = 48
NH₄NO₃ = 80 g/mol
n = 1.25/80 = 0.015625 mol
So,
ΔH = 25*4.18*(25.8 - 21.9)/0.015625
ΔH = 26,083.2 J/mol
ΔH = +26.08 kJ/mol
Answer:
The answers are
1. Scientists use seismometers to measure the earthquake activity that occurs beneath a volcano. They then predict the eruption of that volcano.
2. Scientists measure the amount of these gases to determine the amount of magma present in the volcanic reservoir.
Explanation:
When a volcano is near eruption Earthquake activity gets stronger and stronger. Scientists use a wide variety of techniques to monitor volcanoes, including seismographic detection of the earthquakes and tremor that almost always precede eruptions, precise measurements of ground deformation that often accompanies the rise of magma, changes in volcanic gas emissions, and changes in gravity and.
Scientists can use the FTIR or Fourier Transform Infrared Spectrometer to measure dissolved volatile concentrations as described above or can be used to measure several gases emitted from a volcano simultaneously. The device can be used both as an open-path or closed-path system. I had just taken the test and got the question right as well
Explanation:
It represent Alcohol group (—OH)
Well if anything was mixed in it would make his result different. if not, it could have changed the temperature when he mixed it. which would give him either a lower or higher answer