Answer:
81.71%
Explanation:
One mole of propane contains 3 moles of carbon atoms and 8 moles of hydrogen atoms, as seen from the molecular formula of 
. In order to calculate the percent of carbon in propane by mass, we need to remember that %w/w (or percent mass) formula states that:
That is, we need to divide the mass of the component of interest by the total mass of the compound and multiply by 100 to obtain the percentage.
For simplicity, let's take 1 mole of propane and find the mass of 1 mole (hence, we'll be finding the molar mass of propane). To do that, we add the 3 molar masses of carbon and 8 molar masses of hydrogen to obtain a total of:
Now that we have the molar mass of propane, we also need to find the total mass of carbon in 1 mole of propane. We know that we have a total of 3 moles of carbon which corresponds to:
Dividing the mass of carbon present by the total mass of the compound will yield the mass percentage as defined by the formula we introduced:
Answer:
A
Explanation:
Remember the number of valence electrons represent the group number. As shown in figure, there is only one electron in the valence shell. Therefore, this element belongs to group 1 elements also called as Alkali metals.
Furthermore, the number of electrons in a neutral atom equals number of protons. Hence, there are 11 protons in this element.
Also, number of protons equal atomic number therefore, the atomic number of this element is 11. And, by checking periodic table, the element having atomic number 11 is Sodium (Na).
Answer: No hydrogen bond cannot occur in this alpha helix structure.
Explanation: For hydrogen bond to form, the electronegativity difference should be more than 1.7. carbon has an electronegativity of 2.5 whereas hydrogen has 2.1 so their electronegativity difference is 0.3. So in this alpha helix structure cannot occur.
Answer:
B. The reactants will react to produce more H₂O
Explanation:
Given the reaction
2H₂+O₂→2H₂O
A decrease in the amount of H₂O will cause the reaction to produce more H₂O. When you change something, the reaction seeks to undo that change.
Answer:
NaOH
Explanation:
Sodium Hydroxide (Caustic Soda) is a base. It shares many characteristics of bleach: Albeit more powerful.
