Answer:
1.71 × 10²¹ molecules
Explanation:
1 gram is equal to 1000 milligrams. The mass in grams corresponding to 500 mg is:
500 mg × (1 g / 1000 mg) = 0.500 g
The molar mass of ascorbic acid is 176.12 g/mol. The moles corresponding to 0.500 grams of ascorbic acid are:
0.500 g × (1 mol/ 176.12 g) = 0.00284 mol
In 1 mole of ascorbic acid, there are 6.02 × 10²³ molecules of ascorbic acid (Avogadro's number). The molecules in 0.00284 moles are:
0.00284 mol × (6.02 × 10²³ molecules/ 1 mol) = 1.71 × 10²¹ molecule
Answer:
1) Endothermic.
2)
3)
Explanation:
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1) In this case, for these calorimetry problems, we can realize that since the temperature decreases the reaction is endothermic because it is absorbing heat from the solution, that is why the temperature goes from 22.00 °C to 16.0°C.
2) Now, for the total heat released by the reaction, we first need to assume that all of it is released by the solution since it is possible to assume that the calorimeter is perfectly isolated. In such a way, it is also valid to assume that the specific heat of the solution is 4.184 J/(g°C) as it is mostly water, therefore, the heat released by the reaction is:
3) Finally, since the enthalpy of reaction is calculated by dividing the heat released by the reaction over the moles of the solute, in this case NH4Cl, we proceed as follows:
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There’s lots of measurements. (m, kg, s, mol, cm, in, mm) etc