During the big band only the lightest elements were formed – hydrogen<span> and </span>helium<span> along with trace amounts of </span>lithium<span> and </span>beryllium<span>.</span>
Answer : The initial volume was, 71.2 mL
Explanation :
To calculate the volume when temperature and pressure has changed, we use the equation given by combined gas law.
The equation follows:

where,
are the initial pressure, volume and temperature of the gas
are the final pressure, volume and temperature of the gas
We are given:
![P_1=0.85atm\\V_1=?\\T_1=66^oC=[66+273]K=339K\\P_2=0.60atm\\V_2=94mL\\T_2=43^oC=[43+273]K=316K](https://tex.z-dn.net/?f=P_1%3D0.85atm%5C%5CV_1%3D%3F%5C%5CT_1%3D66%5EoC%3D%5B66%2B273%5DK%3D339K%5C%5CP_2%3D0.60atm%5C%5CV_2%3D94mL%5C%5CT_2%3D43%5EoC%3D%5B43%2B273%5DK%3D316K)
Now put all the given values in above equation, we get:


Therefore, the initial volume was, 71.2 mL
Answer:
OD. 2HCl
Explanation:
A balanced equation needs the equal # of each element on BOTH sides.
By putting a 2 in front of HCl you now have 2 hydrogens on both sides and 2 chlorines. The Ca and CO3 are already balanced.
<span>This would be the activation energy. This is usually in the form of heat, which allows the reaction to undergo some sort of transition. Many times, enzymes can be used as catalysts to lower the activation energy required for the reaction to take place.</span>
The balanced chemical reaction is written as :
Na2CO3<span> + 2HCl === 2NaCl + H2O + CO2
</span>
We are given the amount of NaCl to be produced from the reaction. This will be the starting point for the calculations. We do as follows:
120 g NaCl ( 1 mol / 58.44 g) ( 1 mol Na2CO3 / 2 mol NaCl)( 105.99 g / 1 mol ) = 1108.82 g Na2CO3 needed