D.
The products will have at least 2 Na atoms and 1 O atom.
<h3>Further explanation</h3>
If we refer to the law of mass conservation, which states that
<em>In a closed system, the masses before and after the reaction are the same
</em>
then the number of atoms in the reactance will be the same as the number of atoms in the product
In this problem it is known that Na₂O is one of the reactants so that the product of Na atoms and O atoms will at least equal the number of atoms in the bond, namely 2 Na and 1 O
Like an example of this Na₂O reaction:
Na₂O + H₂O ⇒ 2 NaOH
Na : left =2, right = 2
O : left=2, right = 2
We are given that the balanced chemical reaction is:
cacl2⋅2h2o(aq) +
k2c2o4⋅h2o(aq) --->
cac2o4⋅h2o(s) +
2kcl(aq) + 2h2o(l)
We known that
the product was oven dried, therefore the mass of 0.333 g pertains only to that
of the substance cac2o4⋅h2o(s). So what we will do first is to convert this
into moles by dividing the mass with the molar mass. The molar mass of cac2o4⋅h2o(s) is
molar mass of cac2o4 plus the
molar mass of h2o.
molar mass cac2o4⋅h2o(s) = 128.10
+ 18 = 146.10 g /mole
moles cac2o4⋅h2o(s) =
0.333 / 146.10 = 2.28 x 10^-3 moles
Looking at
the balanced chemical reaction, the ratio of cac2o4⋅h2o(s) and k2c2o4⋅h2o(aq) is
1:1, therefore:
moles k2c2o4⋅h2o(aq) = 2.28
x 10^-3 moles
Converting
this to mass:
mass k2c2o4⋅h2o(aq) = 2.28
x 10^-3 moles (184.24 g /mol) = 0.419931006 g
Therefore:
The mass of k2c2o4⋅<span>h2o(aq) in
the salt mixture is about 0.420 g</span>
Answer:
$200.0 is the cost for installing a carpet for a room that measures 12.0 feet by 15.0 feet.
Explanation:
Length of the room = l = 15.0 ft = 
Width of the room = w = 12.0 ft = 
(1 yard = 3 feet)
Area of the room = l × w = 
Cost for installing a carpet for a room = $10 per square yard
Cost for installing a carpet for a room wit area 20.0 square yard :

$200.0 is the cost for installing a carpet for a room that measures 12.0 feet by 15.0 feet.
Kinetic energy is the energy possessed by an object due to its motion. If an object is moving, then it has kinetic energy. If an object has kinetic energy, then it is moving. Many students confuse kinetic energy with potential energy.