Answer: 
Explanation:
Heat of combustion is the amount of heat released when 1 mole of the compound is completely burnt in the presence of oxygen.
To calculate the moles, we use the equation:
Thus 
of sucrose releases = 916.6 J of heat
1 mole of sucrose releases =
of heat
Thus ∆H value for the combustion reaction is
Answer:
1.40 M [OH⁻]
Explanation:
This compound dissociates into 3 ions, but since we are asked about [OH⁻], it's only 2. Therefore, multiply the molarity of the solution by the number of ions that [OH⁻] dissociates into:
2 × 0.70 M = 1.40 M
Hope this helps! Sorry that you got a link. Those are getting really annoying
Since the beaker was heated we can asume that only magnesium cloride is left in the beaker, therfore the difference between the beaker with magnesium chloride and the empty beaker give the mass of magnisium chloride:
1. The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon.
2.The Precambrian was originally defined as the era that predated the emergence of life in the Cambrian Period.
3. During the Precambrian era the earth started cooling and the outer edge of the planet solidified from molten lava to a solid crust. Water rained from the atmosphere and created oceans.
4. It is The first and longest subdivision of time for the earth.
5. The earth took form about 4.5 billion years ago. For the first 4 billion years of that time, the Earth was growing and changing.
6. he only multi-cellular life forms at the end of the Precambrian were in the oceans and included some groups that have survived until the present: jellyfishes and segmented worms.
7. The discovery of 3.85-billion-year-old marine sediments and pillow lavas in Greenland indicates the existence of liquid water and implies a surface temperature above 0 °C (32 °F) during the early part of Precambrian time.
8. The Precambrian encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4 billion to about 541 million years ago.
9. Precambrian rocks on most continents have revealed that additional primitive life-forms existed approximately 3.5 billion years ago.
10. The earliest evidence for the advent of life includes Precambrian microfossils that resemble algae, cysts of flagellates, tubes interpreted to be the remains of filamentous organisms, and stromatolites (sheetlike mats precipitated by communities of microorganisms).
The heat released by reaction : C) -8870 J
<h3>Further explanation</h3>
Given
1.008 g of hydrogen
500.00 g water
The temperature rises 25.00 °C to 29.24 °C
Required
energy required
Solution
Q absorbed by water :
Q = m.c.Δt
Q = 500 g x 4.18 J/g C x (29.24-25)
Q = 8870.08 J
The reaction to produce HCl is an exothermic reaction (releasing heat), so that Q is negative
Q water = -Q HCl = -8870.08 J
