For which characteristic was this Chinese shar-pei MOST LIKELY selectively bred?

Please answer fast!!! what does base stand for in science

pychu [463]

There are multiple meanings for a base. A base can be a substance that accepts hydrogen ions, or it could be something that is not acidic, in other words meaning its pH is between 7 and 14.

8 0

3 years ago

Gaseous methane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water. If 2.59 g of water is produc

max2010maxim [7]

Answer: The percent yield of the water is 31.98 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For methane:

Given mass of methane = 6.58 g

Molar mass of methane = 16 g/mol

Putting values in equation 1, we get:

$\text{Moles of methane}=\frac{6.58g}{16g/mol}=0.411mol$

For oxygen gas:

Given mass of oxygen gas = 14.4 g

Molar mass of oxygen gas = 32 g/mol

Putting values in equation 1, we get:

$\text{Moles of oxygen gas}=\frac{14.4g}{32g/mol}=0.45mol$

The chemical equation for the combustion of methane is:

$CH_4+2O_2\rightarrow CO_2+2H_2O$

By Stoichiometry of the reaction:

2 moles of oxygen gas reacts with 1 mole of methane

So, 0.45 moles of oxygen gas will react with = $\frac{1}{2}\times 0.45=0.225mol$ of methane

As, given amount of methane is more than the required amount. So, it is considered as an excess reagent.

Thus, oxygen gas is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction

2 moles of oxygen gas produces 2 moles of water

So, 0.45 moles of oxygen gas will produce = $\frac{2}{2}\times 0.45=0.45$ moles of water

Now, calculating the mass of water from equation 1, we get:

Molar mass of water = 18 g/mol

Moles of water = 0.45 moles

Putting values in equation 1, we get:

$0.45mol=\frac{\text{Mass of water}}{18g/mol}\\\\\text{Mass of water}=(0.45mol\times 18g/mol)=8.1g$

To calculate the percentage yield of water, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of water = 2.59 g

Theoretical yield of water = 8.1 g

Putting values in above equation, we get:

$\%\text{ yield of water}=\frac{2.59g}{8.1g}\times 100\\\\\% \text{yield of water}=31.98\%$

Hence, the percent yield of the water is 31.98 %

4 0

2 years ago

What is 0.0000000652 in scientific notation?

Alex787 [66]

Answer:

it denotes 6.52× 10⁸ in scientific notation

8 0

2 years ago

Read 2 more answers

Does anyone know how to answer this or what the answer is? My sister is having a hard time figuring this out with her tutor?

ira [324]

Its number four.Hope that helps feel free to ask me questions:)

Brainliest??

8 0

2 years ago

1. You have 19.7 grams of a material and wonder how many moles were formed. Your

Alex777 [14]

Answer:

No. If you were to set up what the friend said it would look like this:

19.7g × $\frac{grams}{moles}$ ==> $\frac{19.7 grams}{1}$ ×

The above does not look right because the grams do not cancel out. If it's not cancelled, it would be included in your final answer, but you're looking for moles not grams.

When setting up a stoichiometry equation, you have to put the same unit of measurement (ex- grams, cm, mm, etc.) on the numerator of one side and the denominator of the other side.

This would cancel out the unit.

For example: If you wanted to find out how much of 320 cm are in a meter.

*there are 100 cm in 1 meter*

(1. always start with the given number!)

(2. set up the next fraction where you can cancel out cm)

$\frac{320cm}{1}$ × $\frac{1 meter}{100 cm}$ = 3.2 m

Going back, your friend would have to switch the units from grams/moles to moles/grams. It would cancel out grams, which would leave moles. Therefore, moles will be included in your final answer.

$\frac{19.7 grams}{1}$ × $\frac{moles}{grams}$ = _?_ moles

5 0

2 years ago