<span>The mass of one mole of sodium bicarbonate (aka NaHCO3) is equal to 1 * 22.99g/mol + 1 * 1.00g/mol + 1 * 12.01g/mol + 3 * 16.00g/mol = 83.91g/mol. From this, we can convert 4.2g of NaHCO3 to moles by dividing by 83.91g/mol, to get 0.050 moles of sodium bicarbonate.</span>
Hello there!
The statement that Acid strength in a series of H-A molecules increases with increasing size of A is True.
When only the size is involved, increasing the size will increase the Acid strength because as size increases, the H-A bond will become weaker as the atoms will be farther apart. Acid strength is related to the ability to release H⁺ ions and a weaker H-A bond will release H⁺ more easily.
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Answer:
A
Explanation:
To label an element correctly using a combination of the symbol, mass number and atomic number furnishes some important information about the element.
We can obtain these information from the element provided that correct labeling of the element is presented. Firstly, after writing the symbol of the element, the atomic number is placed as a subscript on the left while the mass number of the atomic mass is placed as a superscript on the same left.
Looking at the question asked, we have the element symbol in the correct position as Ca, with 42 also in the correct position which is the mass number. The third number which is 20 is thus the atomic number of the element.
A residue from a gunshot is most likely gun powder, which tells you what kind of bullet was shot and the type of gun that was used to shoot the target/victim/person. Some complications may be that there is more than one gun or weapon which uses that residue, so it may be hard to pinpoint it and the bullet can't really tell you who it is unless there's DNA on the bullet, and the chemicals of the bullet may even destroy evidence.
Distance = 1500m, time = 14min 34.56s = 14*60 + 34.56 = 874.56s
Speed = Distance / time = 1500/874.56 = 1.715 m/s
In order to swim 0.7 miles, 1 mile = 1609.344 m
Time = Distance / speed = 1609.344 m / 1.715 m/s = 938.393 seconds
938/60 = 15 minutes, 38 seconds.
= 15 minutes 38.393 seconds.
