【单选题】
表面吸附是指:___
A. 处于液体表面的分子所受的力与液体内部分子不同;
B. 溶质在溶液表面的浓度与溶液本体的浓度不同;
C. 溶质的加入使表面张力下降;
D. 溶质的加入使表面张力上升
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相关试题
【单选题】
凝固点降低实验中,下列说法正确的是:___
A. 溶液有过冷现象,溶剂则没有
B. 溶剂和溶液冷却过程中都有温度不变的平台期
C. 溶液过冷太甚,对测定结果无影响
D. 溶剂过冷太甚,对测定结果有影响
【单选题】
对于乙酸乙酯皂化反应下列哪种说法是不正确的?___
A. 乙酸乙酯皂化反应是二级反应;
B. 随着反应进行,溶液电导率不断下降;
C. 在此反应溶液中,CH3COONa是不完全电离的;
D. 体系的电导率值的减少量和CH2COONa的浓度增大成正比。
【单选题】
丙酮碘化反应速率方程中,下列哪种物质的浓度与反应速率无关?___
A. 丙酮浓度
B. H+浓度
C. 碘的浓度
D. 无
【单选题】
电动势的测定实验中,为测定以下电池Zn|ZnSO4(0.1000mol·L-1)‖Hg2Cl2|Hg的电动势,选用下列哪种溶液作为盐桥为最好:___
A. K2SO4
B. KNO3
C. KCl
D. KAc
【单选题】
粘度法不是测分子量的绝对方法,是因为:___
A. 粘度法中所用特性粘度与分子量间的经验方程要用其它方法来确定;
B. 溶剂分子间存在内摩擦力;
C. 大分子化合物分子间、溶剂分子间和大分子物分子与溶剂分子间均存在内摩擦力;
D. 溶液的粘度与大分子化合物结构、溶剂及大分子的分子量分布范围等多种因素有关。
【单选题】
蔗糖转化反应本应为二级反应,之所以可以将其看作一级反应是因为:___
A. 蔗糖的初始浓度与反应的快慢无关;
B. 蔗糖与葡萄糖有旋光性,而果糖无旋光性;
C. 产物果糖的左旋性比葡萄糖的右旋性大;
D. 水的浓度可认为保持不变。
【单选题】
溶液的旋光度与下列哪个因素无关?___
A. 温度;
B. 压力;
C. 光源的波长;
D. 样品管的长度。
【单选题】
“溶液表面吸附的测定”实验中,气泡逸出速度略偏快以及逸出速度非常快时,则测得的最大压力差___。
A. 不变、偏大
B. 偏小、偏大
C. 偏大、偏小
D. 偏大、不变
【单选题】
溶液表面吸附实验中,某一组实验发现,所测最大压力差明显偏大,且无气泡产生,最可能的原因是___。
A. 滴液速度太快
B. 系统漏气
C. 加样液面太高
D. 毛细管尖端被堵住
【单选题】
当溶液的电导率为0.4μS/cm时,应选用___。
A. 铂黑电极
B. 光亮铂电极
C. 甘汞电极
D. 无
【单选题】
某同学做蔗糖转化实验时,记录反应开始的时间比实际时间偏晚,对测定反应速率常数k值有无影响?___
【单选题】
希托夫法测定离子迁移数实验中,中间管中的硫酸溶液浓度在通电后比通电前___。
【单选题】
不同分子的动力学稳定性可以用下列哪个能量值比较?___
A. 分子总能量
B. EHOMO
C. ELUMO
D. EHOMO-ELUMO
【单选题】
粘度法测量大分子化合物的分子量时,一般要求液体流出时间()时,测量结果较为准确。___
A. 大于80秒
B. 大于100秒
C. 大于120秒
D. 大于150秒
【单选题】
粘度法实验中,当用外推法做图求[η]值时,如ηsp/C、lnηr/C与y轴三条直线不能相交于一点时,应该用哪两条直线交点作为[η]值较为准确___。
A. ηsp/C与lnηr/C的交点
B. ηsp/C与y轴的交点
C. lnηr/C与y轴的交点
D. 无
【单选题】
丙酮碘化反应速率方程中,下列哪种物质的浓度与反应速率无关?___
A. 丙酮浓度
B. H+浓度
C. 碘的浓度
D. 无
【单选题】
电解质NaCI对渗析前的Fe(OH)3胶体(用水解法制备)的聚沉值与渗析后的聚沉值相比,___
A. 渗析前的聚沉值大
B. 渗析后的聚沉值大
C. 聚沉值相等
D. 无
【判断题】
粘度法测大分子化合物分子量的实验中,选用毛细管的粗细与实验测量所得结果准确度无关
【判断题】
“溶液表面吸附的测定”实验中,如体系有漏气现象,则所测液体的表面张力偏低
【判断题】
乙酸乙酯皂化反应速率常数可以用电导法测定是因为该反应溶液的电导率由NaOH的浓度决定
【判断题】
丙酮碘化反应速率常数可用分光光度法测定是因为反应物及产物中只有碘在550nm左右可见光波段有吸收
【判断题】
在电动势测定实验中,如将标准电池的正负极接反,会造成电路短路
【判断题】
纯溶剂的表面张力最大,加入溶质后,溶液的表面张力下降
【判断题】
凝固点降低实验中,空气套管的作用是防止溶液出现过冷现象,如出现过冷,则实验应重做
【判断题】
采用活性炭吸附醋酸溶液中的醋酸测定活性炭的比表面积,在较高温度下容易达到吸附平衡
【判断题】
“粘度法测大分子的分子量”实验中,测蒸馏水的流出时间时,加蒸馏水的量不需要准确测量
【判断题】
粘度法测大分子分子量实验中,可以改用U型粘度计按同样方法测量大分子的分子量
【判断题】
在“蔗糖转化”实验中,测α∞时,将反应体系放在55—60℃的恒温箱中搅拌5分钟后,立即测α∞
【判断题】
蔗糖转化实验中,若不用蒸馏水校正仪器零点,对测定结果无影响
【判断题】
Fe(OH)3胶体电泳实验过程中负极颜色渐渐变深,正极渐渐变黄,这主要是因为胶体带正电荷向负极移动而引起的
【判断题】
当胶体的电导率很小并采用KNO3作辅助电解质时,正极上的电极反应为H2O-2e=1/2O2+2H+
【判断题】
采用活性炭吸附醋酸溶液中的醋酸测定活性炭的比表面积,在较高温度下容易达到吸附平衡
【判断题】
“丙酮碘化”实验中,从盐酸加入容量瓶中时开始计时,对实验结果有影响
【判断题】
在实验数据处理时,如有部分数据偏差太大则可以舍去,但舍去的数据不能超过实验总数据的10%
【判断题】
测定水的硬度时,需要对Ca、Mg进行分别定量
【判断题】
对某项测定来说,它的系统误差大小是不可测量的
【判断题】
金属离子指示剂与金属离子生成的络合物过于稳定称为指示剂的封闭现象
推荐试题
【多选题】
Which two components are part of storage I/O multipathing on ESXi? (Choose two.)___
A. SATP
B. VASA
C. PSP
D. VAAI
【多选题】
Which two statements are true about Highly Available vSphere Auto Deploy infrastructure? (Choose two.)___
A. It helps prevent data loss.
B. It is a prerequisite for using vSphere Auto Deploy with stateful install.
C. It requires two or more Auto
D. eploy servers.
【多选题】
The virtual machine log rotation size can be changed for all VMs by which two interfaces? (Choose two.)___
A. PowerCLI
B. vSphere Web Client
C. ESXi host client
D. esxcli
【多选题】
Which two configuration options can exclude virtual disks from snapshot operations? (Choose two.)___
A. Use RDM in virtual mode for virtual disk.
B. Use virtual disks in Independent – Persistent mode.
C. Use a virtual disk larger than 2 TB in size.
D. Use RDM in physical mode for virtual disk.
【多选题】
Which two storage configurations on the source server are unsupported with VMware Converter? (Choose two.)___
A. Linux LVM
B. software RAID
C. GPT/MBR hybrid disks
D. Windows basic volumes
E. Windows dynamic volumes
【多选题】
Which two statements about vCenter HA are correct? (Choose two.)___
A. ESXi 5.5 or later is required.
B. vCenter HA network latency between nodes must be less than 50 ms.
C. NFS datastore is supported.
D. It must be deployed on a 3
E. SXi host cluster with DRS enabled.
【多选题】
An attempt to delete NFS datastore from a ESXi host returns the error: Sysinfo error on operation returned the following status:< Busy> Which two statements could explain this failure? (Choose two.)___
A. NFS datastore is a part of Storage DRS Cluster.
B. NFS.VolumeRemountFrequency value is set to 30.
C. Storage I/O Control is enabled on NFS datastore.
D. NFS datastore has running or registered virtual machines.
【多选题】
An administrator finds that the Microsoft Exchange virtual machines are exhibiting network latency. What two in-guest changes can help decrease latency? (Choose two.)___
A. LRO
B. TSO
C. SR-IOV
D. PVRDMA
【多选题】
Which two types of iSCSI adapters require VMkernel networking configuration? (Choose two.)___
A. dependent hardware
B. in-guest
C. software
D. independent hardware
【多选题】
Which two statements are true for NFS v4.1 firewall behavior? (Choose two.)___
A. It closes port 2049.
B. It sets allowed. All flag to TRUE.
C. It sets allowed. All flag to FALSE.
D. It opens port 2049.
【多选题】
A vSphere Administrator attempts to enable Fault Tolerance for a virtual machine but receives the following error: Secondary VM could not be powered on as there are no compatible hosts that can accommodate it. What two options could cause this error? (Choose two.)___
A. The other ESXi host(s) are in Maintenance Mode.
B. Hardware virtualization is not enabled on the other ESXi host(s).
C. The other ESXi host(s) are in Quarantine Mode.
D. Hardware MMU is enabled on the other
E. SXi host(s).
【多选题】
Storage capabilities be populated in what two ways? (Choose two.)___
A. The administrator can use tags to describe capabilities.
B. Default capabilities are provided by vCenter Server.
C. Datastores can advertise their capabilities through VAAI.
D. Datastores can advertise their capabilities through VASA.
【多选题】
In network troubleshooting it is important to know what upstream switch the ESXi host is connected to. Which two features does ESXi provide to help identify the upstream switch? (Choose two.)___
A. Promiscuous mode
B. DPM
C. LLDP
D. CDP
【多选题】
Virtual Volumes supports which three VMware features? (Choose three.)___
A. Instant Clones
B. Distributed Resource Scheduler
C. Linked Clones
D. vMotion
E. Storage Distributed Resource Scheduler
【多选题】
vSphere DRS helps to balance virtual machines with available resources in a vSphere cluster. What three types of resources can be taken into account for balancing? (Choose three.)___
A. CPU
B. physical NIC saturation of an ESXi host
C. virtual NIC saturation of a virtual machine
D. RAM
E. storage latency
【多选题】
Which three design requirements must be satisfied to enable RAID-6 objects in a VMware vSAN cluster? (Choose three.)___
A. vSAN Advanced license or higher
B. vSAN stretched cluster
C. at least six hosts contributing storage
D. deduplication and compression
E. all flash configuration
【多选题】
When using "Cluster resource percentage" for host failover capacity in vSphere HA Admission Control, the total resource requirements are calculated from which two values? (Choose two.)___
A. Total vCPUs assigned to each VM.
B. Average CPU usage on each VM over time.
C. Memory reservations on each VM.
D. Total memory assigned to each VM.
E. Average active memory on each VM over time.
F. CPU reservations on each VM.
【多选题】
Which are four attributes of the Active vCenter HA node? (Choose four)___
A. It uses the vCenter HA network to communicate with the Witness node.
B. It constantly replicates vPostgres data with the Witness node.
C. It uses a public IP address for the management interface.
D. It runs the active vCenter Server Appliance instance.
E. It uses the vCenter HA network for replication of data to the Passive node.
F. It provides a quorum to protect against split-brain situations.
【多选题】
Which are two vCenter Server two-factor authentication methods? (Choose two.)___
A. RSA SecurID
B. Smart Card
C. SAML
D. Symantec VIP
【多选题】
An administrator is creating VMkernel adapters on an ESXi 6.5 host and wants to create separate VMkernel adapters for every type of traffic in the default TCP/IP stack. Which three types of traffic can be explicitly enabled on a separate VMkernel adapter? (Choose three.)___
A. Virtual SAN traffic
B. NFS traffic
C. vMotion traffic
D. vSphere HA traffic
E. Fault Tolerance logging traffic
【多选题】
When migrating a Windows vCenter Server 6.0 to the vCenter Server Appliance 6.5, which two will be migrated by default? (Choose two.)___
A. Local Windows OS users and groups
B. Configuration
C. Custom ports
D. FQDN
E. Historical and Performance data
【多选题】
Which three types of Content Libraries exist within vSphere 6.5? (Choose three.)___
A. Remote Content Library
B. Published Content Library
C. Local Content Library
D. Shared Content Library
E. Subscribed Content Library
【多选题】
An administrator cannot enable multi-processor Fault Tolerance (SMP-FT) for a virtual machine. Which are two possible causes for this? (Choose two.)___
A. The virtual machine is running on a vSAN datastore.
B. The Fault Tolerance network is using a 10Gbit uplink.
C. The virtual machine has 6 vCPUs assigned.
D. The virtual machine has a 1TB VMDK attached.
E. The virtual machine has snapshots present.
【多选题】
Which two statements are true for Predictive DRS? (Choose two.)___
A. It balances resource utilization for virtual machines with unpredictable utilization patterns.
B. It integrates DRS with vRealize Operations Manager to balance workloads for virtual machines before resource utilization spikes occur.
C. It balances resource utilization based on a threshold's algorithm that runs each night.
D. It determines the best placement and balance of virtual machines based on a threshold's algorithm that runs each night in vCenter Server 6.5 Database.
【多选题】
Which two situations could cause a virtual machine to appear with (orphaned) appended to its name? (Choose two.)___
A. if a host failover is unsuccessful
B. if a virtual machine was removed from vCenter Server's inventory
C. if a virtual machine was deployed from template, and the template has been deleted
D. if a virtual machine is unregistered directly on the host
【多选题】
Which three requirements are needed to apply RAID 5 or RAID 6 erasure coding on a vSAN 6.2 or 6.5 object? (Choose three.)___
A. on Disk Format 3.0
B. Hybrid vSAN
C. All Flash vSAN
D. vSAN Advanced License
E. Stretched Cluster Configurations
【多选题】
An administrator sees the following error in the log files: Which two events could be the source of the error message? (Choose two.)___
A. vCenter Server failure
B. VXLAN failure
C. Disk array failure
D. Network failure
E. ESXi host failure
【多选题】
An administrator is attempting to access an ESXi host via the DCUI but is unable to do so. Which could be two possible causes? (Choose two.)___
A. The host in Qhas no out-of-band management capability (i.e. iLO/iDRAC).
B. The SSH service is disabled on the host.
C. Strict lockdown mode is enabled on the host.
D. Normal lockdown mode is enabled and the administrator is a member of the
E. xception User list.
【多选题】
Which two permissions are required to migrate a virtual machine with Storage vMotion? (Choose two.)___
A. Network > Move Network
B. Virtual Machine > Inventory > Move
C. Resource > Migrate powered on virtual machine
D. Datastore > Allocate Space
【多选题】
Which are three supported storage requirements for vCenter Server HA? (Choose three.)___
A. NFS
B. RDM
C. vSAN
D. VMFS
E. JBOD
【多选题】
Which are the two network requirements for a VMware vSAN 6.5 cluster? (Choose two.)___
A. Multicast must be enabled on the physical switches and routers that handle vSAN traffic.
B. vSAN requires IPv6 only.
C. All hosts must have a dedicated 40GbE NIC.
D. The vSAN network supported IPv4 or IPv6.
E. vSAN requires IPv4 only.
【多选题】
Which three prerequisites must be in place prior to enabling secure boot for a virtual machine? (Choose three.)___
A. VirtualMachine.Config.Settings privileges
B. an encrypted USB drive
C. Virtual Hardware version 13 or later
D. Virtual Hardware version 12 or later
E. EFI firmware
【多选题】
A user is given the "Virtual machine user (sample)" role in a vSphere 6.x environment. Which three permissions would the user be able to perform? (Choose three.)___
A. Reset a virtual machine.
B. Power on a virtual machine.
C. Move a host into a cluster.
D. Configure CD media.
E. Migrate a virtual machine with Storage vMotion.
【多选题】
Which three are supported upgrade processes for ESXi host? (Choose three.)___
A. using vSphere Auto Deploy
B. using a TFTP server
C. using Update Manager
D. using an
E. SXCLI command
【多选题】
When enabling Storage DRS on a datastore cluster, which three components are enabled as a result? (Choose three.)___
A. Space load balancing among datastore within the datastore cluster.
B. Initial placement for virtual disks based on space and I/O workload.
C. I/O load balancing among datastores within the datastore cluster.
D. Queue Depth alerting on disks within the datastore cluster.
E. Data de-duplication within the datastore cluster.
【多选题】
What are two features introduced in Network I/O Control version 3? (Choose two.)___
A. Bandwidth reservation per traffic type
B. Network resource pools
C. CoS tagging
D. Bandwidth guarantee to virtual machines
【多选题】
Which two correct virtual machine advanced configuration parameters will accomplish this? (Choose two.)___
A. isolation.device.edit.disable = “FALSE”
B. isolation.device.edit.disable = “TRUE”
C. isolation.device.connectable.disable = “FALSE”
D. isolation.device.connectable.disable = “TRUE”
【多选题】
Which three statements are correct regarding booting an ESXi Host from Fibre Channel SAN? (Choose three.)___
A. Direct connect topology is supported.
B. Each host must have its own boot LUN.
C. ESXi hosts do not require local storage.
D. Multipathing to a boot LUN on an active-passive array is supported.
E. Hosts can share one common boot LUN.
【多选题】
Which two tasks should a vSphere administrator perform if the vmkernel log reports VMFS metadata errors? (Choose two.)___
A. contact VMware technical support
B. reformat the datastore
C. check the device with VOMA
D. ignore the messages
【多选题】
Which two statements are true for a vCenterServer user account that is used for vSphere Data Protection (VDP)? (Choose two.)___
A. The user account must be assigned with Administrator role.
B. The password for the user account cannot contain spaces.
C. The user account should be created in the Single Sign-On domain
D. The user account cannot inherit required permissions from a group role.