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IRINA_888 [86]
3 years ago
13

When helium was discovered by humans?

Chemistry
1 answer:
saul85 [17]3 years ago
8 0
Helium was discovered in 1868.
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Please help, any and all is very much appreciated!
iogann1982 [59]
1. True
2. False
3. False
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5. True
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7. All of the above
8. According to their reactivity with other substances
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3 0
3 years ago
When 4.5 mol al react with 11.5 mol hcl, what is the limiting reactant, and how many moles of h2 can be formed?
ahrayia [7]
1°/ . 2 Al + 6 HCl → 2 AlCl3 + 3 H2 

<span>k1 = n(Al) / 2 = 4,5 / 2 = 2,25 </span>
<span>k2 = n(HCl) / 6 = 11,5 / 6= 1,92 </span>

<span>k2 < k1 ==> HCl is the limiting reactant </span>

<span>6 mol of HCl ---> 2 mol of H2 </span>
<span>11,5 mol of HCl ---> 3,83 mol of H2 </span>
5 0
3 years ago
Use the balanced equation given below to solve the following problem; Calculate the volume in liters of CO produced by the react
Elan Coil [88]

Answer: 40.3 L

Explanation:

To calculate the moles :

\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}

\text{Moles of} Sb_2O_3=\frac{175g}{291.5g/mol}=0.600moles

Sb_2O_3+3C\rightarrow 2Sb+3CO  

According to stoichiometry :

1 moles of Sb_2O_3 produces = 3 moles of CO

Thus 0.600 moles of Sb_2O_3 will produce=\frac{3}{1}\times 0.600=1.80moles  of CO

Volume of CO=moles\times {\text {Molar volume}}=1.80moles\times 22.4L/mol=40.3L

Thus 40.3 L of CO is produced.

6 0
3 years ago
Julio earns $300 a week working a summer job. The paycheck he deposits in the bank is for $250. Which of these accounts for the
azamat

Answer:

theirs a $50 tax with the income hes making

Explanation:

5 0
2 years ago
Read 2 more answers
Which family in the periodic table has elements that are silvery and lustrous?
IrinaVladis [17]
The correct answer is A. Alkali metals.
I hope this helped
6 0
3 years ago
Read 2 more answers
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