Answer:
120.0 kJ
Explanation:
- First we convert the given mass of C to moles:
30.00 g C ÷ 12g/mol = 2.5 mol
- The ΔH° value given by the problem, is the heat absorbed when 5 moles of C react.
So when we have<u> half the moles of C</u> (2.5 instead of 5.0), t<u>he heat absorbed will also be half</u>, thus the answer is:
Ne because as we go in period atomic radius decreases
Answer:
Explanation:
To convert from moles to grams, we must use the molar mass.
Recall that water's molecular formula is H₂O. It contains hydrogen and oxygen. Look up the two elements masses on the Periodic Table.
- Hydrogen (H): 1.008 g/mol
- Oxygen (O): 15.999 g/mol
Now, use these masses to find water's mass. The subscript of 2 tells us there are 2 atoms of hydrogen, so we multiply hydrogen's mass by 2 and add oxygen's.
- H₂O= 2(1.008 g/mol) + 15.999 g/mol = 18.015 g/mol
Use the molar mass as a ratio.
Multiply by the given number of moles.
The moles of water will cancel.
Round to the nearest whole number. The 0 in the tenth place tells us to leave the number as is.
There are about <u>54 grams</u> of water in 3 moles.
There is 1 OH- in 1 molecule of NaOH.
Also, there is 1 H+ in 1 molecule of lactic acid.
So the reaction is simple.
so just equate the moles
moles of OH- in NaOH = moles of H+ in lactic acid
26.8 x 0.07 = 250 x Mole of lactic
Moles of lactic = 0.0075
so mass = 0.0075 x 90.8 = 0.681 g
Answer:
C) Covalent bonds come about because of a sharing of electrons; ionic bonds do not.
Explanation:
There are two main types of chemical bonds- covalent and ionic/electrovalent bonds.
Ionic bond: Ionic or electrovalent bonds are characterized by the transfer of electrons from electropositive atoms (metals) to electronegative atoms (non-metals). The metal atoms after donating their electrons become positively charged ions (cations) while the non-metal atoms after accepting electrons become negatively charged ions (anions). Strong electrostatic forces of attraction constitutes ionic bonds.
Covalent bond: Covalent bonds are formed by the sharing of electrons by the atoms involved in the bond; usually between atoms of comparable electronegativities or atoms of the same element. The shared electrons are contributed by each of the atoms involved in the bonding or may be contributed by only one of the atoms. In covalent bonding, molecules rather than ions are formed.
