Answer:
Explanation:
At 5 s the body has travelled 10 m.
Between 5 s and 10 s, the body reached 30 m.
Distance travelled = 30 m - 10 m = 20 m
Time = 10 s - 5 s = 5 s
What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? Hint: The pKa of phosphate is 6.86.
1 answer:
Answer:
The pH value of the mixture will be 7.00
Explanation:
Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,
According to the given conditions, the equation will become as follow
The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.
Placing all the given data we obtain,
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Answer:
1. a chemical reaction in which one substance breaks up into two or more new substances: decomposition reaction
2. a reaction in which two or more substances combine to form a new substance: synthesis reaction
3. the reaction of an acid with a base to form a salt and water: neutralization reaction.
4. chemical compound formed when the negative ions from an acid combine with the positive ions of a base: salt
5. two ionic compounds reacting in solution to form two new compounds, one of which is insoluble: double displacement reaction.
6. a reaction in which an active metal displaces a less active metal or hydrogen from a compound solution (or a nonmetal replaces a nonmetal from a compound in solution): Single replacement reaction
Explanation:
1. Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.
Example:
2. Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.
Example:
3 and 4. Neutralization is a chemical reaction in which an acid and a base reacts to form salt and water. Salt is formed when cations or positive ions of base combine with anions or negative ions of acid.
Here is the salt formed by combination of
from base and
from acid.
Example:
5. A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
Example:
6. Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
Example: