Answer:
Explanation:
q= mc theta
where,
Q = heat gained
m = mass of the substance = 670g
c = heat capacity of water= 4.1 J/g°C
theta =Change in temperature=(
66-25.7)
Now put all the given values in the above formula, we get the amount of heat needed.
q= mctheta
q=670*4.1*(66-25.7)
=670*4.1*40.3
=110704.1
Answer is: A. Chemical energy to electromagnetic energy and thermal energy.
Balanced chemical reaction: 2Mg(s) + O₂(g) → 2MgO(s) + energy.
This is chemical change (chemical reaction), because new substance (magnesium oxide MgO) is formed, the atoms are rearranged and the reaction is followed by an energy change (exothermic reaction because energy is released).
Chemical changes (chemical synthesis) is when a substance combines with another (in this example magnesium and oxygen) to form a new substance.
The balanced equation given is:
4NH3 + 3O2 .....> 2N2 + 6H2O
From this equation, we can note that 4 moles of NH3 are required to produce 2 moles of N2.
Therefore, the mole ratio of NH3 to N2 is 4:2 which can be simplified into 2:1
10 g of glue with 13 g of water ,
Mass ratio of the material can be calculated as:
8 g of sodium borate suspended in 11 g of water, mass ratio can be calculated as:
Answer: 0,4278g of F and 0,4191g of Fe
Explanation: it's possible to calculate the mass of each element by multiplying the percentage (decimal) of the element by the mass of the compound.
For Fluorine (F)
0,847g * 0,5051 = 0,4278g of F
For iron (Fe)
0,847 * 0,4949 = 0,4191g of Fe
This is determined because even when the compound is decomposed, due to conservative law of mass, the decomposition process do not affect the amount of matter, so the mass of the elements remain even if they are separated from the original molecule.
At the end, the sum of the elements masses should be the total mass of the compound.
