Answer:
Methane is a chemical compound with the molecular formula CH4. It is the main component in natural gas. Methane is considered the simplest of alkanes, compounds that consist only of hydrogen (H) and carbon (C) elements. Methane is an odorless, colorless, tasteless gas that is lighter than air.
Explanation:
The answer is C because you don’t have to worry about the number in front of the decimal unless it is something greater than zero. A- Doesn’t have there sig figs. B- The zero after the 5 doesn’t change it. D- The three at the end doesn’t matter because it does not round it up.
Answer:
The answer to your question is: Initial temperature of copper = 67.1°C
Explanation:
Data
mass Copper = 248 g
volume Water = 390 ml
T1 water = 22.6°C
T2 = 39.9°C
T1 copper = ?
Specific heat water = 1 cal/g°C
Specific heat copper = 0.092 cal/g°C
Formula copper water
Heat is negative for copper because it releases heat
- mCp(T2 - T1) = mCp(T2 - T1)
- (248)(39.9 - T1) = 390 (1)((39.9 - 22.6) Substitution
-9895.2 + 248T1 = 390(17.3) Simplification
-9895.2 + 248T1 = 6747
248 T1 = 6747 + 9895.2
248 T1 = 16642.2
T1 = 16642.2 / 248
T1 = 67.1 °C Result
4. A
because PbCl2 is an ionic compound and it's solid, so it's a substance.
It cannot be mixture, because it's a pure molecule.
5. D
despite that both substances are gases, colorless they are different molecules, so they should have different either chemical and physical properties
6. C
this substance made from W atoms and others are made from molecules
Temperature change, colour change, releasing gas, bubbles and change in odor
