Answer:
In both cases, the gas evolved is H2. When calcium reacts with water the heat evolved is not suffcient for hydrogen to catch fire. On the other hand, sodium metal reacts with water violently and in this case a lot of heat is evolved which is sufficient for hydrogen to catch fire.
Explanation:
may this answer is helpful for you
Answer:
The mass of the products left in the test tube will be less than that of the original reactants.
Explanation
The equation for the reaction is
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
1.0 3.0 3.9 0.1
Assume you started with 1.0 g of Mg.
It will react with 3.0 g of HCl to form 3.9 g of MgCl2 and 0.1 g of H2
.
Mass of reactants = mass of products
1.0 g + 3.0 g = 3.9 g + 0.1 g
4.0 g = 4.0 g
The Law of Conservation of Mass is obeyed.
However, your test tube and its contents will weigh 0.1 g less than it did before the reaction.
Does that contradict the Law of Conservation of Mass? It does not.
One of the products was the gas, hydrogen, and it escaped from the test tube. You weren't measuring all the products, so test tube and its contents weighed less than before.
Explanation:
The end goal of this question is to find density. Density can be found using the following formula:
D=m/v
D=Density
m=mass
v=volume
Therefore we need mass and volume to find density. Mass is already given in the question as 142g. All we have left is volume. When a solid is placed in water in a graduated cylinder the volume goes up. This means if you subtract the volume after the metal was placed from before it was placed, you can find the volume of the metal. Therefore the volume of the metal is 40mL-20mL=20mL. However typically, volume is found in liters so the volume should be .04L-.02L=0.02L. Now that we have volume and mass we can find density using the formula d=m/v. So 142/.02=7,100 grams per liget or 7.1 kilograms per liter. This answer seems unrealistic so I would double check with your teacher about the question.
Hope I helped, 2Trash4U
Answer:
The pressure will be 933.33 Kpa
Explanation:
Given that:
Volume V₁ = 200 cm³ (note, there is a mistake in the volume. It is supposed to be 200 cm³)
Pressure P₁ = 700 Kpa
Pressure P₂ = ??? (unknown)
Volume V₂ = 150 cm³
Temperature = constant
Using Boyle's law:
PV = constant
i.e.
P₁V₁ = P₂V₂
700 Kpa × 200 cm³ = P₂ × 150 cm³
P₂ = (700 Kpa × 200 cm³)/150 cm³
P₂ = 933.33 Kpa
Answer:
I think c
Explanation:
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