Can someone answer this for me and show proof I WILL MARK BRAINLIEST

CH4(g)+O2(g)→CO2(g)+H2O(g). What mass of water is produced from the complete combustion of 5.00×10−3 g of methane?

bixtya [17]

Answer:

1gram of water

Explanation:

First balance the equation

Ch4+2O2>CO2+2H2O

Ratio is 1:2

500×10-3what about 2?

500×10-3×2=1g

1g of water

4 0

3 years ago

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.

AlekseyPX

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,

$pH=pK_{a} + log(\frac{[Base]}{[Acid]})$

According to the given conditions, the equation will become as follow

$pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})$

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,

$pH=6.86 + log(\frac{0.058}{0.042})$

$pH=7.00$

5 0

3 years ago

In a chemical change

Vsevolod [243]

Answer:

B. materials change their properties.

Explanation:

In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.

A chemical change is one in which new kind of matter is formed.

It is always accompanied by energy changes.

Chemical changes are not reversible.
They lead to the production of new kinds of matter
It involves mass changes
Requires considerable amount of energy

8 0

3 years ago

What is chemistry? I NEED HELP ASAP!

Thepotemich [5.8K]

the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances.the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances.

3 0

3 years ago

A graduated cylinder was filled with 25.0 mL of water. A solid object was immersed in the cylinder, raising the water level to 3

yawa3891 [41]

Answer:

Density of the object is 8759.494 grams/L

Explanation:

As we know density of an object is mass of the object divided by its volume

Given

Volume of the object is equal to the change in volume of water with in the cylinder when the object was immersed in water.

Hence, volume of object is equal to

$32.9 -25 = 7.9$ mL