Question

An element \(X\) reacts with oxygen to form \(\mathrm{XO}_{2}\) and with chlorine to form \(\mathrm{XCl}_{4} \mathrm{XO}_{2}\) is a white solid that melts at high temperatures (above \(\left.1000^{\circ} \mathrm{C}\right)\). Under usual conditions, \(\mathrm{XCl}_{4}\) is a colorless liquid with a boiling point of \(58^{\circ} \mathrm{C}\). (a) \(\mathrm{XCl}_{4}\) reacts with water to form \(\mathrm{XO}_{2}\) and another product. What is the likely identity of the other product? (b) Do you think that element \(X\) is a metal, nonmetal, or metalloid? Explain. (c) By using a sourcebook such as the CRC Handbook of Chemistry and Physics, try to determine the identity of element \(\mathrm{X}\).

Short answer

(a) The likely identity of the other product when XCl₄ reacts with water is hydrogen chloride (HCl). The balanced equation is: \(XCl_4 + 2H_2O \rightarrow XO_2 + 4HCl\). (b) Element X is likely a metalloid, based on the properties of its compounds. (c) Element X is germanium (Ge), a metalloid, based on the information obtained from the CRC Handbook of Chemistry and Physics.

Step-by-step solution

Determine the product from the reaction of XCl₄ with water

When XCl₄ reacts with water, it forms XO₂ and another product. We can deduce that the other product should be an acid, since XO₂ is a basic metal oxide. Let's write down the reaction equation: \(XCl_4 + H_2O \rightarrow XO_2 + ?\) Since XO₂ is formed, we can deduce that the remaining elements, H, and Cl should combine to form the acid. The likely product is hydrogen chloride (HCl), which is a common acid. So, the balanced equation should be: \(XCl_4 + 2H_2O \rightarrow XO_2 + 4HCl\)

Determine if X is a metal, nonmetal, or metalloid

We can deduce if X is a metal, nonmetal, or metalloid by analyzing its properties. We know that XO₂ is a white solid that melts at high temperatures, above 1000°C. This is a characteristic of a metal oxide. XCl₄ is a colorless liquid with a boiling point of 58°C, which suggests that the element X has a low reactivity. These properties hint that X is likely a metalloid rather than a metal or nonmetal. However, to be more certain, we need to cross-check this information with a standard reference like the CRC Handbook of Chemistry and Physics.

Identify element X using the CRC Handbook of Chemistry and Physics

Using the CRC Handbook of Chemistry and Physics or a similar reference, one can look for a metal, nonmetal, or metalloid that forms compounds such as XO₂ and XCl₄ and matches the given properties. Element X is germanium (Ge), a metalloid. Germanium forms germanium dioxide (GeO₂) and germanium tetrachloride (GeCl₄), which match the properties of the compounds described in the question. For example, germanium dioxide is a white solid with a high melting point of 1115°C and germanium tetrachloride is a colorless liquid with a boiling point of 83.1°C. The slight difference in boiling point from the given value can be attributed to varying impurities and experimental conditions. In conclusion, element X is germanium (Ge), a metalloid.

Key concepts

Compound Reaction with Water

Understanding how compounds react with water is crucial in chemistry, as it gives insights into the behavior of substances and their potential applications or hazards. A classic example is when a metal chloride reacts with water, often producing a metal oxide and an acidic by-product, as seen in the step-by-step solution for the reaction of element X's chloride, \(XCl_4\rightarrow XO_2 + 4HCl\). This particular reaction reveals the formation of hydrogen chloride (HCl), emphasizing how recognizing patterns in chemical reactions helps predict the products. When conducting such an experiment or analysis, always consider the conservation of mass and charge to ensure the equation is balanced.

Students should feel comfortable predicting reaction outcomes by recalling that water, a polar molecule, often initiates the breakdown of ionic compounds, releasing ions into the solution. For instance, salts like \(XCl_4\) usually dissociate into their respective ions when in contact with water, providing a visual cue for the kind of reactions taking place.

Properties of Metalloids

Metalloids are elements with properties intermediate between metals and nonmetals, making them an intriguing topic in chemistry. They have a unique set of characteristics, such as variable conductivity and reactivity. As shown in the solution, the properties of element X suggested it was a metalloid: it formed a high melting point oxide which is typical for metalloid oxides and a low boiling point chloride, representative of lesser volatility than expected for typical nonmetals.

Students should recognize the importance of metalloids in technology, particularly germanium (Ge) and silicon (Si), which are extensively used in electronic components due to their semi-conducting properties. Recognizing these properties helps in categorizing elements and predicting their chemical behavior, a key skill for advancing in chemistry.

Metal Oxide Characteristics

Metal oxides are compounds formed by metals reacting with oxygen. They typically demonstrate high melting points, solid-state at room temperature, and basic behavior, as seen with the white solid \(XO_2\). These oxides may react with acids to form salts and water, a reaction known as neutralization. The exercise showcased this fundamental concept with the melting point of \(XO_2\), indicative of substantial ionic character and lattice energy, traits often found in metal oxides.

Students should be aware that metal oxides play a pivotal role in various industrial processes, from acting as catalysts to serving as raw materials for creating metals. Understanding their characteristics is not only essential for identifying unknown compounds but also for grasping the connections between chemical properties and practical applications.

Using CRC Handbook for Chemistry Research

When identifying unknown elements or compounds, resources like the CRC Handbook of Chemistry and Physics are invaluable. This comprehensive reference contains physical, thermodynamical, and chemical data on a vast number of substances. For chemistry learners, familiarizing oneself with such resources is key to substantiating hypotheses with empirical data, as seen in the final step of the textbook solution, where the CRC Handbook confirmed element X as germanium (Ge) due to its properties and compounds' data.

Students should build a habit of using credible sources to verify chemical information, whether it's molecular weights, melting/boiling points, or reactivity trends. This approach not only solidifies theoretical knowledge but also introduces best practices for conducting accurate and reliable chemistry research.