Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
Answer:
CH3OH and NADH
Explanation:
The given chemical reaction is an redox reaction in which reduction and oxidation take place.
In the process of oxidation: electrons are loss while in the process of reduction: electrons are gained.
In the given redox reaction: CH3OH + NAD --> CH2O + NADH
NAD is reduced to NADH as NADH gains one hydrogen electron while CH3OH (methanol) is oxidized to CH2O (methanal) by losing electrons.
So, CH3OH (methanol) and NADH are the reduced forms while NAD and CH2O (methanal) are oxidized forms.
Since the density of water is 1 g /mL, hence there is 100
g of H2O. So total mass is:
m = 100 g + 5 g = 105 g
=> The heat of reaction can be calculated using the
formula:
δhrxn = m C ΔT
where m is mass, C is heap capacity and ΔT is change in
temperature = negative since there is a decrease
δhrxn = 105 g * 4.18 J/g°C * (-2.30°C)
δhrxn = -1,009.47 J
=> However this is still in units of J, so calculate
the number of moles of NaCl.
moles NaCl = 5 g / (58.44 g / mol)
moles NaCl = 0.0856 mol
=> So the heat of reaction per mole is:
δhrxn = -1,009.47 J / 0.0856 mol
δhrxn = -11,798.69 J/mol = -11.8 kJ/mol
How many grams N2O in 1 mol? The answer is 44.0128. We assume you are converting between grams N2O and mole. You can view more details on each measurement unit: molecular weight of N2O or mol This compound is also known as Nitrous Oxide.
Answer:
0.071L
Explanation:
From the question given, we obtained the following data:
Molarity of HCl = 2.25 M
Mass of HCl = 5.80g
Molar Mass of HCl = 36.45g/mol
Number of mole of HCl =?
Number of mole = Mass /Molar Mass
Number of mole of HCl = 5.8/36.45 = 0.159mole
Now, we can obtain the volume required as follows:
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 0.159mole/ 2.25
Volume = 0.071L
