A compound signifies a substance comprised of two or more elements that have undergone a chemical combination. A polyatomic ion, often referred to as a molecular ion, represents a charged particle formed from two or more atoms. An example would be the nitrate ion (NO3-), which consists of one nitrogen atom and three oxygen atoms covalently bonded, acting as a single charged entity. Thus, the apt term would be a polyatomic ion or a molecular ion.
This procedure entails diluting the 12 molar HCl. To decrease the concentration, we must create an equation to determine how much of the 12M is needed for the 3.5M solution.
12 moles HCl 3.5 moles HCl
——————— = ———————
1 Liter of Soln ‘x’ Liters of Soln
Note that the ratio of 12 moles over 1 liter corresponds to 12 molar; thus, we maintain the original concentration of the HCl. By equating it to the 3.5 over ‘x’, we are still preserving the concentration.
After computation, we determine ‘x’ to be 0.292. This value indicates that within 0.292 liters of our 12 M HCl solution, there are 3.5 moles of HCl. Yet, we are not finished.
0.292 liters of 12 M HCl can create 1 liter of 3.5 M HCl, but the inquiry demands 1.5 liters. To achieve this, multiply 0.292 liters by 1.5, resulting in 0.4375, which denotes the quantity of 12 M HCl necessary to prepare a 1500 mL 3.5 M HCl solution.
The amount of heat needed to elevate an object's temperature can be determined using the formula,
heat = mass x specific heat x (T2 - T1)
Thus, specific heat can be found with the following formula,
specific heat = heat / (mass x (T2 - T1))
By substituting,
specific heat = 645 J / ((28.4 g)(15.5 - - 11.6))
The calculated specific heat from the above equation is 0.838 J/g°C.