Answer:
1.18×10²³ atoms.
Explanation:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms.
From the above concept, 1 mole of sodium also contains 6.02×10²³ atoms.
1 mole of sodium = 23 g.
Thus,
23 g of sodium contains 6.02×10²³ atoms.
Therefore, 4.5 g of sodium will contain = (4.5 × 6.02×10²³)/23 = 1.18×10²³ atoms.
From the above calculation,
4.5 g of sodium contains 1.18×10²³ atoms.
Answer:
Explanation:
Hello,
In this case, we define the entropy change for such freezing process as:
Thus, we compute the moles that are in 5.590 g of liquid mercury:
Hence, we compute the required entropy change, considering the temperature to be in kelvins:
Best regards.
Explanation:
For Mg, (1.2 g Mg/24 g Mg) = 0.05 mol Mg.
For Cl, (3.55 g Cl/35.5 g Cl) = 0.1 mol Cl
So the ratio now is
Mg:Cl = 0.05 : 0.1 = 1:2
I got the 1:2 ratio by dividing both by the smallest number, which is 0.05 mol. Therefore, the empirical for formula of the substance is
Answer:
Explanation:
2Ca is the elemental form of calcium. There are 2 mols of calcium in whatever equation you are talking about.
Ca_2 means that there are 2 ions of Calcium making up something like
Ca3(PO4)2 means that you have the compound Ca3(PO4)2 with 2 mols of PO4 and 3 moles of Ca
It is hard to come up with something composed of Ca2 because unless the other ion is odd, the 2 will divide into something.
The correct answer is D) ) It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added.
The statement that describes how a basic coffee cup calorimeter works is: "It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added."
To measure the heat flow during a chemical reaction we use the device called Calorimeter. This device has a combustion chamber and above it, a metal container of water. With the use of a thermometer, we can measure the change in temperature. The combustion chamber releases the heat. This increases the temperature of the water.
The other options of the question were A) It measures the mass of a substance given the specific heat and temperature of water in a cup of known size. B) It measures the density of a substance given the mass, specific heat, and temperature of water in a cup of known size. C) It uses the mass and specific heat of water along with a pressure gauge to measure the gain or loss of energy when a substance is added.