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nekit [7.7K]
3 years ago
10

Hi guys I need an science matter experiment to do at school. For example which chocolate is best to take at a hot climate? Dark,

white or milk?
I need something WOW.
Chemistry
1 answer:
inysia [295]3 years ago
3 0
Dark is the strongest chocolate.
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The ________ ion has eight valence electrons. the ________ ion has eight valence electrons. cr6+ ni6+ fe6+ co6+ mn6+
statuscvo [17]
Answer is: Cr⁶⁺.
₂₄Cr 1s²2s²2p⁶3s²3p⁶3d⁵4s¹.
₂₄Cr⁶⁺ 1s²2s²2p⁶3s²3p⁶. 8 valence electrons.
₂₈Ni 1s²2s²2p⁶3s²3p⁶3d⁸4s².
₂₈Ni⁶⁺ 1s²2s²2p⁶3s²3p⁶3d⁴.
₂₆Fe 1s²2s²2p⁶3s²3p⁶3d⁶4s²
₂₆Fe⁶⁺1s²2s²2p⁶3s²3p⁶3d².
₂₇Co 1s²2s²2p⁶3s²3p⁶3d⁷4s²
₂₇Co⁶⁺ 1s²2s²2p⁶3s²3p⁶3d³.
₂₅Mn⁶⁺ 1s²2s²2p⁶3s²3p⁶3d¹.
7 0
3 years ago
Which of the following is most appropriate in measuring the mass of a cow; kilogram, gram or meter? Explain your answer with det
Blababa [14]
The most appropriate unit to take the weight of a cow would be kilograms.

Meters are a unit of distance and are not applicable here
A gram is too small to use in this instance
7 0
3 years ago
Read 2 more answers
A volume of 129 mL of hydrogen is collected over water. The water level in the collecting vessel is the same as the outside leve
mixas84 [53]

Explanation:

As it is given that water level is same as outside which means that theoretically, P = 756.0 torr.

So, using ideal gas equation we will calculate the number of moles as follows.

                  PV = nRT

or,           n = \frac{PV}{RT}

                 = \frac{\frac{756}{760}atm \times 0.129 L}{0.0821 Latm/mol K \times 298 K}

                  = 0.0052 mol

Also,  No. of moles = \frac{mass}{\text{molar mass}}

               0.0052 mol = \frac{mass}{2 g/mol}

                  mass = 0.0104 g

As some of the water over which the hydrogen gas has been collected is present in the form of water vapor. Therefore, at 25^{o}C

                P_{\text{water vapor}} = 24 mm Hg

                                = \frac{24}{760} atm

                                = 0.03158 atm

Now,   P = \frac{756}{760} - 0.03158

              = 0.963 atm

Hence,   n = \frac{0.963 atm \times 0.129 L}{0.0821 L atm/mol K \times 298 K}

                 = 0.0056 mol

So, mass of H_{2} = 0.0056 mol × 2

                         = 0.01013 g (actual yield)

Therefore, calculate the percentage yield as follows.

      Percent yield = \frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100

                              = \frac{0.01013 g}{0.0104 g} \times 100            

                              = 97.49%

Thus, we can conclude that the percent yield of hydrogen for the given reaction is 97.49%.

3 0
3 years ago
A binary compound of boron and hydrogen has the following percentage composition: 78.14% boron, 21.86% hydrogen. If the molar ma
algol [13]

Answer:

Empirical formula: BH3

Molecular Formula: B2H6

Explanation:

To solve the exercise, we need to know how many boron atoms and how many hydrogen atoms the compound has. We know that of the total weight of the compound, 78.14% correspond to boron and 21.86% to hydrogen. As the weight of the compound is between 27 g and 28 g, using the above percentages we can solve that the compound has between 21.1 g and 21.8 g of boron, and between 5.9 g and 6.1 g of hydrogen:

100% _____ 27 g

78.14% _____ x = 78.14% * 27g / 100% = 21.1 g boron

100% ______27 g

21.86% ______ x = 21.86% * 27g / 100% = 5.9 g hydrogen

100% _____ 28 g

78.14% _____ x = 78.14% * 28g / 100% = 21.8 g boron

100% _____ 28g

21.86% _____ x = 21.86% * 28g / 100% = 6.1 g hydrogen

So, if the atomic weight of boron is 10.8 g, there must be two boron atoms in the compound that sum 21.6 g. The weight of hydrogen is 1 g, so the compound must have six hydrogen atoms.

The molecular formula represents the real amount of atoms that form a compound. Therefore, the molecular formula of the compound is B2H6.

The empirical formula is the minimum expression that represents the proportion of atoms in a compound. For example, ethane has 2 carbon atoms and 6 hydrogen atoms, so its molecular formula is C2H6, however, its empirical formula is CH3. Therefore, the empirical formula of the boron compound is BH3.

8 0
3 years ago
Pure substance can be __ and __
Aleksandr [31]
It can be an element or a compound
4 0
3 years ago
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