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Julli [10]
2 years ago
7

Which TWO observations are evidence that a chemical change is happening?

Chemistry
1 answer:
Kryger [21]2 years ago
7 0

Answer: it is B and D light

Explanation: when a spark happens that is changing and bubbles is also changing

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What mass of HBO2 is produced from the<br> combustion of 139.5 g of B2H6?<br> Answer in units of g.
aliina [53]

Answer:

m_{HBO_2}=441.8gHBO_2

Explanation:

Hello there!

In this case, since the combustion of B2H6 is:

B_2H_6+3O_2\rightarrow 2HBO_2+2H_2O

Thus, since there is 1:2 mole ratio between the reactant and product, the produced grams of the latter is:

m_{HBO_2}=139.5gB_2H_6*\frac{1molB_2H_6}{27.67gB_2H_6} *\frac{2molHBO_2}{1molB_2H_6} *\frac{43.82gHBO_2}{1molHBO_2}

m_{HBO_2}=441.8gHBO_2

Best regards!

5 0
2 years ago
What is the name of CF4?.
Mumz [18]

Answer:

please mark me as brainlest

Explanation:

carbon fluoride is the answers

8 0
2 years ago
Read 2 more answers
Given the following unbalanced chemical reaction: As + NaOH Na3AsO3 + H2 What would be the coefficient of the NaOH molecule in t
barxatty [35]

Answer: -

6

Explanation: -

The given unbalanced chemical equation is As + NaOH -- > Na3AsO3 + H2

We see there 3 sodium on the right side from Na3AsO3.

But there are only 1 sodium on the left from NaOH.

So we multiply NaOH by 3.

As + 3 NaOH -- > Na3AsO3 + H2

Now we see the number of Hydrogen on the left is 3.

But the number of hydrogens is 2 on the left.

So, we multiply to get both sides 6 hydrogen.

As + 6NaOH -- > Na3AsO3 + 3 H2

Rebalancing for Na,

As + 6NaOH -- > 2Na3AsO3 + 3 H2.

Finally balancing As,

2 As + 6 NaOH -- > 2Na3AsO3 + 3H2

The coefficient of the NaOH molecule in the balanced reaction is thus 6

7 0
3 years ago
3) In the Hydrolysis of Disaccharides and Polysaccharides portion of the lab, starch should give one positive iodine test and on
AfilCa [17]

Answer: potassium iodide is the basic test for starch,and the positive test is blue-black coloration, any other test substance which is not starch will give a negative results.

Explanation:

Starch is an example of  polysaccharide  and since the standard test for it is potassium iodide solution, it gives a positive test.

Diasaccharides e.g maltose are reducing sugars.their standard test is BENEDICT test .

Therefore, in the hydrolysis;  starch should give a positve test, while Diasaccharides should give negative rest.

3 0
3 years ago
What is the absorbance of the permanganate in the diluted waste solution?
Snowcat [4.5K]
<span>Not to be confused with tetration. This article is about volumetric titration. For other uses, see Titration (disambiguation). Acid–base titration is a quantitative analysis of concentration of an unknown acid or base solution. Titration, also known as titrimetry,[1] is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator[2] is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand[3] to determine concentration. The volume of titrant reacted is called titration volume</span>
7 0
3 years ago
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