Answer:
K2X
Explanation:
The term valency refers to an element's capacity to combine with other elements. This property determines how an element is represented in a chemical compound's formula.
For magnesium and element X, represented as MgX, magnesium typically has a valency of +2 in its compounds. The absence of the +2 in the formula implies that element X must possess a -2 valency, resulting in a cancellation of the valencies.
Furthermore, potassium is classified as an alkaline metal in group 1 of the periodic table, leading to an expected valency of +1.
When forming a compound with element X, a valency exchange occurs. Since X has a -2 valency, the resulting formula of the compound formed by the exchange will be K2X.
Given parameters:
Mass of sucrose = 5g
Density of sucrose = 1.12g/mL
Percentage of sucrose per liter of cane juice = 12%
Unknown:
Volume of cane juice required =?
We need to understand the relationship between volume and density. Density represents mass per unit volume.
Mathematically;
Density = 
Now, calculate the volume of sucrose;
1.12g/mL = 
Volume = 
= 4.46mL = 4.46 x 10⁻³L since 1000mL = 1L
Since 12% of one liter of cane juice is sucrose,
12% of x liter of cane juice = 4.46 x 10⁻³L
Volume of cane juice = 4.46 x 10⁻³ x 
= 0.037L
Volume of cane juice needed is 0.037L
Specific enthalpy is defined as the overall energy in a system attributed to its temperature and pressure, measured per unit mass. It is essential in thermodynamic calculations when one needs to determine the energy for a specific unit mass of a component.
Specific enthalpy can be computed with the equation:
H = U + PV
For this example, the specific volume is 4.684 cm³/g or 149.888 cm³/g moles, which translates to 149.888 × 10⁻³ J/g moles.
The specific internal energy (U) is 1706 J/mol, and the pressure measured is 41.64.
Calculating gives us H = 1706 + 41.64 × 149.888 × 10⁻³ × 101.3 joules
= 2428 joules / mole
Answer:NH₃/NH₄Cl
Explanation:
The pH of a buffer can be determined using Henderson-Hasselbalch's equation.
![pH=pKa+log\frac{[base]}{[acid]}](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
When the concentration of acid equals that of the base, the pH aligns with the pKa of the buffer. The ideal pH range is pKa ± 1.
Below are the buffers and their corresponding pKa values:
- CH₃COONa/CH3COOH (pKa = 4.74)
Thus, the ideal buffer is NH₃/NH₄Cl.
Explanation:
The scale under her feet exerts an equal force but opposite in direction.
This principle aligns with Newton's third law of motion, which says that "for every action, there is an equal and opposite reaction."
As the girl’s weight presses down on the scale with a force of 42N, the scale responds with an equal upward force in the opposite direction.
The resulting net force is zero, which explains why her weight does not break the scale.
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