1.B
6.D
D because t<span>he mass of one mole (molar mass) of helium gas is </span>4.002602 g/mol. 4.002602 * 5=20.01309. Rounded equals 20. So, the answer is D.20 g.
Answer:
The number of mol is: 0, 042 mol in 4 grams of MgCl2
Explanation:
We calculate the weight of 1 mol of MgCl2:
Weight 1mol of MgCl2= weight Mg + (weight Cl)x 2=
24, 3 grams + 2 x 35, 5 grams = 95, 3 grams/mol MgCl2
95, 3 grams------1 mol MgCl2
4 grams -------x = (4 grams x1 mol MgCl2)/ 95, 3 grams= 0, 04197 mol MgCl2
25 people in an elevator that has a maximum load of 20 people
Answer:
84 Joules are wasted per second.
Explanation:
An efficiency of 16% means 84% is wasted as heat energy.
Therefore;
For a 100W bulb;
Heat wasted = 84/100 × 100 W
= 84 W
Therefore;
84 W or 84 joules are wasted as heat per second
<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f_{(product)}]-\sum [n\times \Delta H^o_f_{(reactant)}]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28product%29%7D%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28reactant%29%7D%5D)
Hence, the correct answer is Option D.
